In a neighborhood dotted with faded "Got Hope?" Obama bumper stickers, where more than half the people live in poverty and where, residents say, most everyone needs "a little hustle" to get by, Willis has it figured out.
She harvests the seeds, salting and baking them, from drooping, late-season sunflowers that she planted in a vegetable garden she tends in a vacant lot across the street. That garden, and one other on the block, serves as part hobby, part food pantry for needy neighbors - and part cash crop.
Willis, 58, grows kale, cabbage, collard greens, tomatoes and butternut squash to make home-cooked meals that she sells for $3 to $5 a plate to a loyal clientele of locals. Many of them struggle financially and suffer from physical and mental ailments, including alcohol and drug abuse.
In pockets of Philadelphia beset by poverty and unemployment, Willis is part of a vast entrepreneurial underground that has gained strength since the 2008 economic downturn, according to agriculture and food-insecurity experts.
"Out here, you got to find ways to make money," Willis said while standing in her garden on the 1300 block of North Dover Street as she inspected a tangle of tomato vines.
For some, the hustle involves a drug trade that feeds a cycle of violence here in the 22nd Police District, where officers responded to roughly 1,530 violent crimes in 2012 - second only to 15th Police District, which topped 1,650. The 15th District covers Frankford, Mayfair and parts of the lower Northeast.
For Willis, who lives off disability checks and food stamps, the hustle is selling meals made with homegrown vegetables and inexpensive bulk ingredients, like sacks of rice and 16-ounce, 98-cent bags of lima beans that she buys at Bottom Dollar at 31st Street and Girard Avenue.
Willis has figured out how to earn a bit of pocket money with her garden and by maximizing her food stamps and stretching her government disability checks. The little money she makes flows back into the economy, in the form of a $10 bus ride to Delaware, where she spends $40 once a month on bingo, hoping to win the $3,000 jackpot.
"I'm a gambler. I like bingo. I'm addicted," she said, offering a shrug of her shoulders and a bemused grin.
Willis' best customers are the street-corner drinkers who favor 40-ounce cans of beer.
"Sometimes I'll sell a dinner of fried fish and potatoes with fresh vegetables from my garden on the side for $5," Willis said. "People will be drinking beer and they'll say, 'I ain't eat all day.' "
She gestures toward Master Street. "These people down at the other corner, they get a little toasty and, like I said, alcohol will make you hungry. And so you'll be all tipsy and you don't want to go inside and cook something to eat, so you just say, 'Well, Miss Paula Mae got beans. Beans and rice and vegetables with smoked turkey necks.' "
On a Friday afternoon late last month, the neighbors who weren't at work gathered along Master near 29th, sitting on front stoops and plastic lawn chairs on the sidewalk drinking 40s wrapped in white plastic bags.
"We have a lot of drinkers that are out here, and her food is good, 'cause it puts a lining in your stomach and it mixes with the alcohol, so you just go to sleep instead of being drunk and crazy out here, right?" said Sonja, 44, a repeat customer who did not want to provide her last name. "A nice hot meal, that will put you to sleep more than anything."
"Her food is delicious," added Lisa Brown, 48. "She's a nice, beautiful lady. She's a clean woman. She's a clean cook."
Community and so-called squatter gardeners, who grow food in abandoned lots, produced about $4.9 million worth of vegetables citywide in summer 2008, according to a University of Pennsylvania study.
"In low-wealth communities, we found gardening is a strategy that many people employ to cope with poverty and its attendant health and social problems," concluded the report's authors, Domenic Vitiello and Michael Nairn of Penn's Planning and Urban Studies Program. "It is one of many ways that people work to address the food needs and wants of their families and neighbors, an important part of building healthier, more resilient cities and communities."
Claire Baker, director of gardening programs at the Pennsylvania Horticultural Society, which runs a program that taught Willis how to garden and got her started with seeds and clean soil, said Willis represents a burgeoning - though largely hidden - network of food providers operating in poor neighborhoods across the city.
"I think that's the story that people don't know," Baker said. "It's been sort of under the radar in terms of the food-security movement, and it's coming to light more now. It became more apparent that there were people in need. People began to think, 'How can we take care of ourselves and each other?' "
Of the city's 46 ZIP codes, 19121, known as "Brewerytown/Fairmount North," has the second-highest number of residents living in poverty, 53.4 percent. That rate is second only to a section of North Philadelphia within the 19133 ZIP code, which tops the list at 54 percent, according to "Philadelphia 2013: The State of the City," an annual report compiled by Pew Charitable Trusts.
"Most of our money goes to pay bills," said one of Willis' neighbors, James Ramsey, 50, who lives off government assistance. "And when you are finished paying bills, you don't have nothing left and you don't want to do no illegal stuff. So you got to get side hustles. You know? You don't want to do nothing illegal. But you gotta get by."
Willis said her own troubles began some two decades ago when she was in her late 30s. She and her husband separated, and she was left to raise four children on her own.
"It was a heavy load," she recalled. She got a job "beating paper," bundling and boxing fliers for a printing company. But she started passing out at work. Stress, the doctor told her.
"I worked there for like five years before I had a nervous breakdown," she said. "People break up all the time but you never expect to be by yourself, and when it happens, you think you can do it. But then, one day, you realize you can't. I was trying to do it all and evidently I couldn't."
She declined to say what she gets each month in Supplemental Security Income. Or reveal the spices she uses to season her crabs, which she sells for $1 each. Or provide the name of the seafood store in Chinatown where she buys clams in 100-bushel sacks. (Her price is $2 for three clams with "a little cup of rice.")
Like others who sell food out of their homes or out of the back of their cars in the underground economy, she worries about attracting too much attention, specifically from the government.
Mariana Chilton, an associate professor and director of the Center for Hunger-Free Communities at the Drexel University School of Public Health, said the welfare system often works against poor people by potentially penalizing creativity.
People like Willis - and there are many operating across the city - prefer to remain off the radar for three reasons: One, if they are collecting disability, they are not supposed to be able to work; two, they are operating without a food or business license and not paying taxes; three, they are not permitted to use their food-stamp allotment to make and sell food to others, according to Chilton.
"There are thousands of people who are doing this kind of thing, and, unfortunately, our system, especially our welfare system, discourages this kind of social entrepreneurship," Chilton said. "The system pushes people to be very suspicious, to stay underground. But if we could find ways to legitimatize this kind of work, this kind of activity and creativity, I think that we could reduce and, in some ways, we could potentially end poverty for people who are able-bodied but can't necessarily work in a traditional way."
Willis has walked around the neighborhood posting signs that advertise her cooking. An advertisement for her clams, stapled to a piece of plywood, reads: "wWHY VIAGREA, U, CAN BUY CLAM 3 4 2.00&."
"My husband loves her clams. That's a good price for clams. They are big and whole," said Sonja, the woman sitting near the corner of Master and 29th streets.
"I don't know about clams being better than Viagra; a fine woman will work for me," Andrew Jackson, 62, said with a sly smile.
Jackson, a former machinist who said he struggles with "mental" illness and can no longer work, described Willis' meals as "reasonable, down-home cooking" that is far better than any takeout food around.
"When she's serving it, we buy it," said Bertram B. Lawson, 56, a former U.S. Marine and retired tailor.
Back near the garden, Ramsey, who uses a cane to get around, citing "bad knees," ambled over to Willis and proclaimed, "Her beans be banging, baby!"
Ramsey then made a pitch for a free plate in exchange for his glowing endorsement. "I'm going to be sweating her."
"Not gonna happen," Willis said, punctuating the sentence with one of her unbridled laughs and mirthful, toothy smiles. "I need that money for bingo. I can't go to the bingo hall and say, 'I need this for free.' "
Willis then turned to a reporter: "This story is never going to make the paper. It's boring."
A free dinner is wagered that it will.
On Twitter: @wendyruderman