30-Minute Stuffed Pepper Soup

This has all the same flavors I remember and love from Stuffed Bell Peppers — that mellowed bitterness from the pepper, the hearty beef, chewy rice, and sweet tomato… it’s comfort in a bowl if I’ve ever seen it!
Ingredients
1 tablespoon olive oil
1/2 medium yellow onion, chopped
1 lb lean ground beef
2 cloves garlic, minced
1 red bell pepper, chopped
1 green bell pepper, chopped
1 (8 oz) can tomato sauce
1 (28 oz) can fire-roasted diced tomatoes, undrained
3 cups beef broth
1 teaspoon Italian seasoning
1/4 teaspoon crushed red pepper flake, optional
2 cups cooked white rice
Kosher salt and freshly ground black pepper, to taste