Grate carrots and beetroot. Set aside.
Chop red bell pepper, mushrooms, avocado, and onion into thin slices. Set aside.
Warm your tortilla in a dry skillet or in the microwave to soften it.
To make the wrap, place the tortilla on a flat surface and spread two tablespoons of mayonnaise over it.
Add a bit of every ingredient in a line, leaving some space at the bottom and sides.
Continue rolling the tortilla until all the filling is on the inside.