The scoop: The tostada is one of the most notoriously calorific entrees in the Mexican food oeuvre. By grilling shells instead of frying them, and cutting out the meat and sour cream, you get a guilt-free, flavorful vehicle for veggies. (If you just can't live without sour cream, the fat-free kind is super low-cal. You can also use a dollop of fat-free Greek yogurt.)
Makes 4 servings
Ingredients: 3 tablespoons olive oil, plus more for grill 3 medium zucchini (1 1/2 pounds total), cut into 1/2-inch-wide slices 4 Portobello mushrooms (1 pound total), stemmed 1 1/2 bunches scallions, root ends trimmed Coarse salt and ground pepper 4 flour tortillas (10-inch or burrito-size) 3 cups store-bought or fresh salsa 1 cup feta cheese, crumbled 1 lime, cut lengthwise into 4 wedges (optional), for serving
Directions: Heat grill to high; lightly oil grates. In separate piles, arrange zucchini, mushrooms and scallions on a baking sheet. Drizzle with two tablespoons oil; season with salt and pepper.
Working in batches if necessary, remove each pile of vegetables from baking sheet. Grill, turning once, until lightly browned and tender, two minutes for scallions, six minutes for mushrooms and eight minutes for zucchini. Return all vegetables to baking sheet. Slice mushrooms into 1/2-inch-wide strips. Set aside.
Brush tortillas with remaining tablespoon oil; grill, turning frequently, until browned and very crispy, about two minutes. Place one tortilla on each serving plate; cover evenly with mushrooms and zucchini. Using kitchen shears, snip scallions over vegetables. Top with salsa, and sprinkle with feta; serve with lime wedges if desired.