Saute the peppers and onions in the olive oil over medium high heat until the peppers are slightly tender and onions turn opaque. About 7 minutes. Sprinkle 1 to 2 tsp of the taco seasoning over the peppers and onions part way through cooking.
Lay the chicken tenders out on a cutting board and, one at a time, pound out the tenders with a meat mallet or the back of a pan until thin and flat. Sprinkle the surface of the tenders with remaining taco seasoning.
To assemble the roll ups, place a small stack of the peppers and onions in the center of a chicken tender. Fold one end over the peppers and onions, then roll over to the other end. Fix the exposed end of the chicken with a toothpick. Sprinkle any remaining seasoning over the tops. Grill over medium high heat for 5-6 minutes on each side. Or bake at 375 for 10-15 minutes until chicken has browned.