Clean and dice up the onion . Slice the peppers into small pieces. Clean and slice the CHICKENbreasts into long strips and place in a bowl.
Add a tbsp of the fajita mix to the chicken breast and mix well.
In a large skillet, heat 1 tbsp of the olive oil and add the chicken to it. Cook the chicken for 5 to 10 minutes until it's fully cooked and no longer pink, and it's slightly charred, but not burned.
Remove chicken from skillet, and wipe the skillet clean.
Add another tbsp of olive oil to the skillet and heat it up. Add the onion and cook for a couple minutes until it's slightly translucent. Add the peppers and the fajita mix and mix well. Cook for a couple more minutes so the peppers cook slightly. Add the chicken to the skillet, mix with peppers and onions and cook for a minute.
In a clean skillet, add a bit of the butter and melt. Add a tortilla and move it around until it's buttery. Add a little bit of the chicken and onion mixture on top of the tortilla, and about ¼ cup of cheese, depending on how you like it. Add another tortilla on top and pat it down.
Now flip it over and cook on the other side until the other side is nice and golden. Remove from skillet and cut into quarters. Repeat these steps with the remaining tortillas. Serve this with sour cream and salsa.