01 - Heat a large skillet over medium-high heat. Add the ground beef and diced onion, breaking the meat apart with a spatula. Cook until evenly browned and no pink remains, approximately 7 minutes.
02 - Drain any excess fat from the skillet. Stir in the ketchup, yellow mustard, garlic powder, salt, and black pepper. Continue cooking for 2 minutes to meld the flavors, then remove from heat.
03 - Soften the flour tortillas by heating them one at a time in a dry skillet over medium heat for 15 seconds per side, or wrap the stack in a damp paper towel and microwave for 30 seconds until pliable.
04 - Lay each warm tortilla flat. Place one slice of cheddar cheese in the center and spoon an equal portion of the seasoned beef mixture over the top.
05 - Layer diced tomato, shredded lettuce, and sliced dill pickles over the beef filling on each tortilla.
06 - Fold in both sides of the tortilla toward the center, then roll tightly from the bottom up to form a secure wrap. Place seam-side down.
07 - Serve the wraps immediately. For a crispy exterior, grill each wrap in a hot skillet seam-side down for 2 minutes per side until golden.