In a medium-sized mixing bowl, whisk together the whole eggs and egg whites. Season with salt and pepper, ensuring mixture is well combined and frothy.
Heat the olive oil in a non-stick skillet over medium heat. Once hot, add the diced bell peppers and sauté for 3-4 minutes, or until they are slightly softened and fragrant.
Reduce the heat slightly, then pour the egg mixture into the skillet over the sautéed bell peppers. Stir gently with a spatula and cook for 4-5 minutes, or until the eggs are fully cooked and have set. As the mixture begins to form curds, gently fold in the rinsed black beans and half of the shredded cheese until everything is evenly mixed and the cheese has melted.
Remove the skillet from the heat and set aside to cool slightly. Meanwhile, prepare a clean surface for assembling the burritos.
Place the tortillas flat on the prepared surface. Using a spoon, distribute the egg and vegetable mixture evenly among the tortillas, being careful to leave about an inch of space along the edges.
On top of the egg filling, add slices of avocado, a generous tablespoon of salsa, and the remaining shredded cheese to each tortilla.
To roll the burritos, fold the sides of the tortilla inward and then begin rolling from the bottom up, securing the filling tightly inside. Aim for a snug fit to prevent spilling.
For an extra touch of flavor and texture, carefully place the burritos seam-side down back in the skillet over medium heat. Toast each side for 2-3 minutes or until golden brown and crispy.
Once toasted, remove the burritos from the skillet and let them cool for a moment. Garnish with a sprinkle of fresh chopped cilantro before serving.
Notes
Serve each burrito cut in half on a plate with extra salsa for dipping.