Grilled Avocado and Veggie Tacos

Name: Grilled Avocado and Veggie Tacos
Ingredients: 1 medium zucchini, cut lengthwise into 1/2-inch slices; 1 medium summer squash, cut lengthwise into 1/2-inch slices; 1 sweet onion, sliced; 1 red bell pepper, cored and cut into quarters; 1 orange or yellow bell pepper, cored and cut into quarters; 2 tablespoons vegetable oil; 1 medium lime, halved; 1 teaspoon ground cumin; 0.5 teaspoon chili powder; 0.25 teaspoon salt; 0.25 teaspoon cayenne pepper; 1 ripe avocado, halved and pitted; 8 (6 inch) corn or flour tortillas, warmed; 0.5 cup crumbled cotija or feta cheese; 1 teaspoon Fresh cilantro