Chicken and Brisket Stew

From Southern Living Magazine Ingredients 2 large onions, chopped 2 garlic cloves, minced 1 tablespoon vegetable oil $ 1 1/2 tablespoons jarred beef soup base 2 pounds skinned and boned chicken breasts $ 1 (28-oz.) can fire-roasted crushed tomatoes 1 (12-oz.) package frozen white shoepeg or whole kernel corn 1 (10-oz.) package frozen cream-style corn, thawed 1 (9-oz.) package frozen baby [...]