Prep onions and peppers by cutting into manageable pieces. Skewer onions and leave peppers in a long flat strip. Coat with oil and salt. Then get grilling...
Grill meat to you liking along with peppers and onions. They should still have some texture to them and a nice charr on the outside. Toss tortillas on for a few seconds at the end.
Let your meat rest for 10 minutes and then slice. Arrange grilled items on a platter along with tortillas and set out with your toppings and sides. Eat up.