Vegan and burger indulgence aren't words usually found in the same sentence. But at Sketch, the edgy Fishtown burger atelier best known for beefy excess (smashed onion burger, mmm . . .), owner-chef Phyllis Farquhar makes great efforts to give her vegan clientele a prime patty experience, too. She experimented for more than a year to perfect her unique vegan burger, which has so many grains (quinoa, oats), beans (seven kinds), veggies (potatoes, carrots, onions), spices (coriander, cumin), herbs (spearmint), and textured vegetable protein inside, it's practically an entire health-food store on a bun. It is remarkably satisfying in flavor, with a deep-fried exterior crisp that makes it taste like the love child of a burger and a falafel - especially with tahini dressing. Polish it off with a sweet wedge of one of Farquhar's marvelously moist vegan cakes - either rich chocolate or tangy red velvet - and you can add the word decadent to that vegan meal, too.