I have a neighbor that makes something close. It is more of a "wrap" and is a lot larger with more veggies. I get dirty looks when I call them fish burritos. She has mixed in the vegetables some kimchi (there is a local store that sells like two dozen varieties of kimchi, from mild to wild) and my favorite is this pickle-onion-jalapeno relish. She will use grilled salmon or tuna and sometimes baked fish like cod or whitefish. She will come up with different sauces to put on them but the grandkids (those that I do not have to twist their arm to eat fish and/or vegetables) like just plain old ranch or thousand island dressing. However her wraps and this recipe from uthunter IMO would make a pretty good summertime lunch, not steaming hot and not over elaborate on the plate. If you had most of the fixings done ahead of time it would be a roll'em up and serve. A great way to use up left over fish. I've even chopped up left over fish sticks and put them into a wrap.
The tricky stuff is best left to those who are highly experienced in operating at the ragged edge of stability and sanity.