Slice bell peppers and onions and place in the bottom of the slow cooker. Then sprinkle 2 tablespoons of the fajita seasoning over the pepper/onion mixture.
Mix well and then place the chicken breast on top. Sprinkle the remaining 1-tablespoon of fajita seasoning on the top of the chicken.
Pour the orange juice in the slow cooker.
Cook for 4 hours on high.
Once the chicken is cooked, remove the chicken, shred, and top with 1 teaspoon fajita seasoning.
Mix in the other 3 teaspoons of fajita seasonings into the vegetables.
Place shredded chicken and (drained) fajita veggies on top of flour tortilla.
Top with sour cream and shredded cheese; repeat until all the fajitas are done!