Sausage: Pan fry according to package instructions. Set aside.
Bacon: Place bacon in a single layer in a large skillet (cold skillet). Set over low heat to slowly render bacon fat, about 2 minutes. Increase to medium heat. Turn bacon strips often to ensure even browning. Cook bacon to your desired crispness. Place bacon on paper towel lined plate to drain. Pour rendered bacon fat into a small bowl and reserve for later use.
Veggies: Add 1 tablespoon of rendered bacon fat into skillet used to cook bacon. Warm over medium heat. Add chopped onions. Cook until almost translucent. Season with a pinch of kosher salt. Toss to combine. The moisture from the onions should help release any bacon drippings on the skillet. Add chopped green bell peppers. Toss to combine. Cook until softened. Remove from heat and transfer veggies to clean bowl.
Eggs: Whisk together eggs, milk, salt, and pepper in a large bowl until thoroughly combined. Heat one tablespoon butter (or neutral oil like grapeseed oil) in a large nonstick skillet over medium heat until warm. Pour in egg mixture and reduce heat to low. Add eggs begin to set, use a spatula to gently push and pull the eggs across the skillet to form soft curds. Continue this process over low heat until there are no longer any liquids. Remove from heat and transfer scrambled eggs to clean bowl.
Assembly: Warm tortillas in the microwave (about 15 seconds) or in a skillet until flexible. Build the burrito by placing two sausage links and one bacon slice towards the bottom third of tortilla. Add ⅛ of scrambled eggs, ⅛ of veggie mix, a small handful of fries, and a generous sprinkling of cheddar.
Fold in the two sides of tortilla. Roll burrito up tightly. Place seam side down on a baking sheet or plate. Repeat with remaining tortillas.
To enjoy immediately: Place burrito seam side down on a skillet set over medium heat for about 2-3 minutes until toasted and seams are sealed shut. Flip burrito to warm and toast other side.
To freeze: Individually wrap burritos in foil. Arrange tightly wrapped burritos in a single layer in a freezer safe plate or baking sheet. Freeze until solid. Transfer burritos to a freezer bag.
To reheat: Remove foil wrapper. Wrap burrito in a moist paper towel and place on a microwave safe plate. Microwave at half power for 90 seconds to 2 minutes on each side, until warmed throughout. If desired, place thawed burrito on skillet to toast.