Vegetarian Burrito Bowl with Avocado Sauce

Name: Vegetarian Burrito Bowl with Avocado Sauce
Ingredients: 3 medium Bell Peppers (sliced); 2 cups Fresh Tomato (chopped); 1 1/2 cups Lettuce (chopped); 2 Avocados (ripe); 1 1/2 Red Onions (divided); 3 Limes (divided); 1 Jalapeno (chopped); 1 cup Fresh Cilantro (chopped); 1 1/2 cups Black Beans (drained and rinsed); 1 1/2 cups Corn (frozen or fresh); 1/2 cup Sour Cream (low fat); 1 cup Brown Rice (small grain); 3 Tablespoons Olive Oil (divided); 1 1/4 teaspoons Garlic Powder (divided); 1 teaspoon Cumin; 1/2 teaspoon Chili Powder; Black Pepper