01 - Combine eggs, milk, salt, and pepper in a medium mixing bowl and whisk until fully blended.
02 - Heat olive oil in a large nonstick skillet over medium heat. Add red onion and red bell pepper; cook for 2 to 3 minutes, stirring occasionally, until vegetables are softened.
03 - Incorporate spinach into the skillet and cook for 1 minute until wilted.
04 - Reduce heat to low. Pour egg mixture into the skillet and gently scramble, stirring frequently, until eggs are softly set, about 3 minutes.
05 - Fold in chopped turkey or chicken breast and black beans. Cook for 1 additional minute to heat through.
06 - Sprinkle shredded cheddar cheese over the filling and gently stir until cheese is completely melted.
07 - Warm tortillas in a dry skillet or microwave for approximately 15 seconds until pliable.
08 - Divide the filling evenly between tortillas. Fold in the sides and roll tightly to form burritos. Serve immediately with salsa, if desired.