Ground beef cauliflower casserole

Name: Ground beef cauliflower casserole
Cuisine: American, TexMex
Ingredients: ½ cup chopped onion; 2 medium yellow pepper, chopped; 1 pound extra lean ground beef; 3 cups bite-size cauliflower florets; 3 cloves garlic, minced; 2 tablespoons chili powder; 2 teaspoons ground cumin; 1 teaspoon dried oregano; ½ teaspoon salt; ¼ teaspoon ground chipotle; 1 (15 ounce) can diced tomatoes; 1 cup shredded cheese; 1/3 cup pickled jalepenos