In a medium bowl, whisk together the eggs, whole milk, salt, black pepper, ground cumin, and smoked paprika until well combined.
Heat the olive oil in a large non-stick skillet over medium heat.
Add the diced red bell pepper, green bell pepper, and yellow onion to the skillet. Sauté for 5-7 minutes until the vegetables are softened.
Add the chopped spinach to the skillet and cook for an additional 1-2 minutes until wilted.
Pour the egg mixture into the skillet with the vegetables. Stir gently and cook, stirring occasionally, until the eggs are fully scrambled and cooked through, about 4-5 minutes.
Remove the skillet from heat and stir in the shredded cheddar cheese until melted and combined.
Warm each flour tortilla in a dry skillet or microwave for about 10 seconds to make them pliable.
Divide the egg and vegetable mixture evenly among the six tortillas, placing the filling in the center of each.
Fold in the sides of each tortilla and then roll tightly from one end to the other to form burritos.
Wrap each burrito individually in plastic wrap or aluminum foil.
Place the wrapped burritos in a freezer-safe container or resealable freezer bag and freeze for up to 3 months.
To reheat, remove the plastic wrap or foil and microwave the burrito on high for 2-3 minutes, turning halfway through, until heated through. Alternatively, reheat in a 350°F oven for 20-25 minutes wrapped in foil.