In a large pot (you will want a pot for this), warm oil at medium heat. (I use extra virgin olive oil).

Cook the sausage until browned or well cooked. Stirring to break it up every once in a while

Once the oil is warmed, add hashbrowns. Cook until nearly done. (Note: This needs to be cooking while the sausage is cooking and can be started before the sausage if you prefer.)

Once the sausage is nearly done, add the onions.

Once both the sausage and hashbrowns are cooked mix them together. (Note: Hashbrowns don't have to be done well.) Try to get as little as possible of the grease from the sausage into the hashbrowns unless you like the flavor of the sausage a lot. It may be added to add some more flavor.

Cook together for 5 minutes if both are done when you mix them, stiring often. If hashbrowns are not done, cook together until done, stiring often.

While the sausage and hashbrowns cook, beat the eggs (note: I use 5 eggs because I have two people who eat a lot and adding more eggs help with their hunger.

Once the 5 minutes are up mix eggs into the hashbrowns and sausage and cook until they are done. Stirring frequently. (I stir it every 30 seconds or so and cook for 5 minutes to ensure that they are done.

Prepare flour tortilla with cheese. Once the hashbrown mixture is done cooking it is time to put it on the tortilla.

This is the way that I cook breakfast burritos while camping. It can be modified for your personal pleasure. I did not add serving size because I feed five people who all add different amounts to their plates and I am not sure what the serving size or yeild would be.
Cook time differs from elivation to how you prefer to cook.