Prepare mac & cheese according to product directions.
Meanwhile, heat a skillet or grill over high heat, greasing with a small amount of fat if not using non-stick. When very hot, place burger patty on the cooking surface and cook both sides until caramelized. Transfer to a cutting board and slice into 4-5 strips.
Lay out a large, burrito-sized tortilla and arrange the burger in the center, followed by approximately ½ cup of the tomato sauce. Top with 1 - 1 ½ cups of the prepared mac & cheese.
Roll into a tightly sealed burrito (see recipe notes for video).
Heat a skillet with a small amount of oil to medium (can use the same skillet used to cook the burger - will impart extra flavor). Place your burrito seam-side down. This will fry the seam shut. Check after 1 minute - you're looking for some GBD (the *highly* technical industry term for Golden-Brown Delicious).
Optional step (but recommended!): Carefully rotate the burrito one-quarter turn. Fry for another minute, or until golden brown. Repeat two more times until you have 4 nicely browned sides (this makes for a crunchy, almost chimichanga-like result).
Plate the Mac 'n Cheeseburgerito, topping with avocado slices or guacamole, green chilies (or green chili hot sauce like Cholula), vegan yogurt/sour cream, and chopped romaine lettuce. Devour with abandon!