Heat skillet on Medium/high. Add 1 tbsp canola oil. Once hot, add garlic and stir frequently until lightly browned. Add onions and continue to sauté.
In large mixing bowl, Add fajita mix to 2T. warm water and 2 t. canola oil. Whisk contents together. Add in peppers and coat peppers entirely with fajita mixture/sauce. Salt and Pepper the mixture (eyeball it). Once coated, add to sautéed onions. Sauté peppers until tender (not mushy). Add more salt and pepper.
In another large mixing bowl, mix together 3/4 cups salsa with 3/4 cups sour cream. Add in steak coat completely. Add 1/2 cup cheese and continue to mix. Add in pepper mixture. Mix all ingredients until completely coated.
Spray 9x13 (or 2 8x8) pan with cooking spray. Heap 4 spoonfuls of filling mix into each tortilla. Roll tightly and place towards edge of pan, seam side down. Once pan is filled with enchiladas, mix together remaining 3/4 cup salsa with 3/4 cup sour cream. Pour over top of enchiladas. Sprinkle remaining 1 1/2 cup cheese on top. *.
Put in oven uncovered. Bake for 25-30 mins, or until tortillas are browned and cheese is completely melted/browned on top.