Knowlton says the most authentic Thai food in the country may come out of a former Dunkin' Donuts in the nation's capital. "It pulls no punches in the level of spiciness." Ordering is simple: $45 for seven courses, no substitutions. It doesn't have a phone number or take reservations, either. littleserow.com
Oxheart
Houston
Tucked beneath Interstate 10, this little spot offers just three fixed-price options. And guests set their own table between courses with silverware - a way to save on costs. The menus are largely vegetable-driven with some Creole influences. But Knowlton particularly likes its use of so-called trash fish -- various Gulf Coast species usually discarded because they're not what fishermen seek. 832-830-8592; oxhearthouston.com
Bäco Mercat
Los Angeles
This downtown eatery takes its name from a bäco, a made-up dish that Knowlton calls a hybrid pizza, taco and gyro. One version is made with Indian naan bread topped with almond-tomato sauce, green sauce, fried pork belly and carnitas. But that's just the start. "It's a globetrotting menu that draws from Mexico to South America to the Mediterranean to Spain." 213-687-8808; bacomercat.com
Cakes & Ale Restaurant
Decatur, Ga.
While this restaurant is a few years old, Knowlton says it qualifies as new because it changed locations and menus, adding incredible pastries. "If a bake sale died and went to heaven, that's what this place looks like." He cites its chewy, gooey brownies, layer cakes and lemon bars. "They're what any true-blooded American would recognize, but it tastes better than anything else they've had." 404-377-7994; cakesandalerestaurant.com