Mix mayo, ketchup, mustard, relish, vinegar, garlic powder, and smoked paprika in a bowl. Chill in the fridge until needed.
Bake or air-fry crinkle-cut fries following the package directions until crispy.
Heat a griddle to medium-high. Add butter and chopped onions. Cook until soft and golden. While that cooks, shape the ground beef into 4 patties.
Place patties on the hot griddle. Smash them flat, add mustard and seasoning, and cook for 3–4 minutes per side. Chop them into small pieces once done.
Lay a tortilla flat. Add sauce, fries, a slice of cheese, chopped beef, onions, another slice of cheese, and more sauce.
Roll them up tightly. Place seam-side down on the griddle. Cook for 2–3 minutes per side until golden and crisp.
Cut in half and enjoy while they’re hot and melty.