And plant-based substitutes stand in for ingredients such as eggs and pepperoni, a hefty sacrifice for lovers of pastry and pizza.
Sounds difficult, even anhedonic. But for Sheller and Paul Hedman, 33, partners for almost four years, cooking and eating vegan is as easy, and delicious, as a carnivorous diet.
"And we are definitely not deprived," says Sheller, who cautions that too much (eggless) white pasta and too many fries (cooked in vegetable oil) can make even a vegan fat.
While Hedman still occasionally enjoys meat or fish, Sheller is consistently vegan, and this guides both daily and party menus. "With wine, lots of wine," she says.
Sheller and Hedman are part of the growing ranks of vegans.
According to a 2012 Harris Interactive telephone survey commissioned by the Vegetarian Resource Group (VRG) in Baltimore, 4 percent of Americans over 18 - 9 million people - are vegetarian; 2 million of those are vegan. In 1994, a similar poll identified only 1.5 percent of the country as vegetarian and vegan.
As recently as the 1980s, according to John Cunningham, the VRG's research manager, "being a vegetarian was shorthand for saying someone was flaky and fringe. These days, if you say you're vegetarian or vegan, you're more likely to hear, 'Wow, wish I could do that.'
"That's a very big change in mind-set," he says.
Sheller was in and out of vegetarianism starting at age 12. In 2006, she became a vegan, motivated by compassion for animals, but also a desire for a healthy diet, waning enthusiasm for meat, and concerns over agribusiness and its environmental impact.
As for Hedman, an environmental chemist who grew up in North Jersey, vegan food is an easy sell, although his buddies sometimes say things like, "Christine is a vegan? How can you live with that?"
He humbly replies, "It's more a question of can she put up with me."
When Sheller gets teased - "eating grass again?" - she reacts good-naturedly, busting the stereotype of the evangelical vegan. "I'm not very judgmental," she says.
This holiday season, the couple's typical party menu might include lentil-walnut-apple loaf, sweet-potato puree, roasted root vegetables, kale salad with oranges, and pear-cranberry crisp.
"It's a very '70s palette, a lot of brown and dark brown, but very delicious," says Sheller, who serves it all on stylish white plates.
Ever the precise scientist, Hedman is a mise en place chef, prepping all the ingredients ahead of time with his prized Japanese usuba knife.
The duo are known for their creative get-togethers - an annual taco party, "trini" (Trinidadian) food night, a "Spanish feast," and a spontaneous mushroom blowout after they bought too many 'shrooms at a festival.
"One of the guys we had for dinner had never eaten mushrooms before - he's a meat-and-potatoes Midwestern kid - but after the meal, he said, 'Everything was delicious,' " Sheller recalls.
Such surprise is common among first-timers, according to Freya Dinshah, president of the 52-year-old American Vegan Society, based in Malaga, Gloucester County.
"People think if you're vegan, the dishes don't taste good. That's not the case at all," says Dinshah, a vegan for 53 years who relishes "the whole adventure and exploration of new foods and new tastes and possibilities."
Fresh ingredients are key. Sheller gets hers from Weavers Way Co-op, with Whole Foods as backup. Her recipes come mostly from the Internet. Favorite sites include vegandad.blogspot.com, theppk.com (post-punk kitchen), and urbanvegan.net - and a certain kitchen in West Chester.
Minus the cheese, of course.
Contact Virginia A. Smith at 215-854-5720 or firstname.lastname@example.org.