At Tacos D.F., a former taco-truck-turned-restaurant-proper, the most extreme torta on the board might be the cubano — a monstrous thing made of ham, milanesa, cheese, beans, lettuce and a whole hot dog, split lengthwise and seared on the grill. But the best is the simple ham with avocado: ham stacked thick on a soft, lardy bun with sliced avocado, shredded lettuce, tomato and a chile-spiked dressing that's like a rémoulade after a semester spent hitchhiking through Chihuahua. It's beautiful, comforting, perfectly balanced — a work of peasant culinary art easily on par with the best, fanciest sandwiches served anywhere in town. Better, maybe, if you get to eat it while sitting in Tacos D.F.'s dining room, watching Mexican game shows on the TV in the corner and surrounded by people who understand that getting the best sometimes means looking in the least likely locations.