Step 1: Prepare the Egg Mixture : In a bowl, whisk together eggs, milk, salt, pepper, and cumin. Heat olive oil or butter in a nonstick skillet over medium heat. Add onions (and bell peppers if using) and sauté for 2–3 minutes until softened. Pour in the egg mixture and cook, stirring gently, until scrambled but slightly soft. Stir in black beans and half the cheese. Remove from heat.

Step 2: Assemble the Taquitos : Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper. Warm tortillas slightly in the microwave (10–15 seconds) to make them pliable. Spoon 2–3 tablespoons of the egg mixture along one edge of each tortilla. Sprinkle with remaining cheese and roll tightly into a log. Place seam side down on the baking sheet.

Step 3: Bake the Taquitos : Brush each taquito lightly with olive oil or melted butter. Bake for 15–20 minutes, flipping halfway through, until golden and crisp.

Step 4: Serve : Serve warm with salsa, guacamole, or sour cream on the side.