Chicken Tacos

Name: Chicken Tacos
Cook time: 30 min
Total time: 30 min
Cuisine: Mexican, TexMex
Ingredients: ¼ cup olive oil; 2 medium yellow onions, (finely chopped); 2 bell peppers, (any color, finely chopped); 4 cloves garlic, (finely chopped); 2 pounds ground chicken ((not extra-lean all breast meat)); 1 tablespoon paprika; 2 teaspoons ancho chili powder; 1½ teaspoons ground cumin; ½ teaspoon dried oregano; 1/8 teaspoon cayenne pepper ((optional)); 1¾ teaspoons salt; 1 (8-oz) can tomato sauce; ½ cup chopped fresh cilantro ((see note)); 12 hard taco shells; 2 cups shredded lettuce or red cabbage ((optional), for topping); 2 cups shredded Mexican cheese blend ((optional), for topping)