Spread 1 Tbsp sour cream in the center of a tortilla and top with 1/6 of the cooked eggs, shredded mozzarella cheese, and sauteed onion & bell peppers. Add 1-2 Tbsp diced tomatoes if using*. Don't over-stuff or they will be tough to roll.
2. Roll the burrito from top to bottom: tightly wrap the top flap over the filling, fold the edges in tightly and role to seal with the bottom flap. Repeat with remaining burritos.