Preheat the oven to 375 degrees. Add the chicken to 2-3 cups water in a pot. Add the chicken bouillon cube and boil for about 20-30 minutes. Remove the chicken and place it in a bowl to cool down.
Once the chicken is cool to the touch, use hands and/or two forks to shred the chicken as thin as possible. Add all of the remaining seasoning to the chicken and mix it until combined.
Next add the onion, 1/4 bag of the Monterrey jack cheese, can of green chiles, mix until combined.
Heat oil in a skillet. Fry corn tortillas for 30 seconds (enough to make them pliable). Remove them from the oil and drain on a paper towel. Heat flour tortillas in the microwave for 320-30 seconds.
Heat and combine the bottle of mild salsa verde, and sour cream in a small sauce pan until it begins to lightly boil. Remove it from the heat and set it aside.
Spray a 9x13 baking dish with nonstick spray. Spread about 1/4 cup of the salsa verde and sour cream mixture into the bottom of the baking dish- just enough to form a thin layer.
Begin filing and rolling each tortilla with the chicken mixture. Spoon the chicken onto one side of the tortilla, and roll them up as tight as possible.
Place the enchiladas in the baking dish seam side down. Pour the remaining green chile sauce over the top of the enchiladas.
Cover with aluminum foil and bake for 20 minutes.
Remove the enchiladas from the oven, take off the foil and sprinkle with remaining Monterrey jack cheese.
Turn the oven on to broil, and put the enchiladas back into the oven to melt and brown the cheese (about 3 minutes). WATCH VERY CLOSELY BECAUSE THEY WILL EASILY BURN.