Heat olive oil in a large nonstick skillet over medium heat. Add onion and bell pepper; cook 5 to 7 minutes until softened.
Stir in black beans, spinach, cumin, garlic powder, smoked paprika, salt, and pepper. Cook 1 to 2 minutes until spinach wilts.
Whisk eggs and milk together until smooth.
Reduce heat to medium-low. Pour eggs into the skillet and gently push from edges to center. Cook 3 to 5 minutes until just set.
Remove from heat and let filling rest 5 minutes.
Warm tortillas 10 to 15 seconds in a dry skillet or microwave briefly under a damp paper towel.
Add 1/2 cup filling below the center of each tortilla. Top with cheese and 1 tablespoon salsa.
Fold in sides, fold bottom flap over filling, and roll tightly to close. Serve immediately, or wrap for storage.
Notes
Chef's Tip: Let the filling cool fully before rolling and wrapping burritos for the freezer; this prevents trapped steam from making the tortilla soggy. Nutrition (approximate, per serving): Calories: 320kcal | Carbohydrates: 28g | Protein: 20g | Fat: 15g | Fiber: 6g | Sugar: 3g | Sodium: 540mgNutrition information is automatically calculated and should be used as an approximation only.