In a large skillet over medium heat, cook the sausage, peppers and onions, crumbling the sausage into small pieces as it cooks, until it is no longer pink and cooked through and the veggies are tender.
Drain the grease (you can let the sausage/veggies hang out in the skillet for a minute or remove them to a plate).
In a medium bowl, whisk together the eggs, milk, sour cream, salt and pepper until smooth. Lightly grease a 9X13-inch baking pan.
Place the tater tots in the bottom of the pan (it's ok if they are overlapping a bit).Sprinkle the sausage and veggie mixture over the tater tots. Pour the egg mixture evenly over and across thetop. Bake right away OR cover the dish and refrigerate (up to 18 hours).
Preheat the oven to 350 degrees F. Bake covered for 25 minutes. Uncover and bake 20-25 minutes longer until golden, bubbly, and set. If freezing the burritos, let the casserole cool until just warm or room temperature.
If serving right away, go right on ahead with step #7.
Scoop about 1/2 cup of the casserole onto each tortilla (if using smaller tortillas, adapt theamount as needed). Sprinkle with shredded cheese. Fold the sides in and roll up into a burrito.Serve warm with avocados, sour cream, and/or salsa, if desired (they're tasty plain, too).