In a large saucepan, add the onion, jalapeno and oil. Cook on medium heat until the vegetables have softened, 8-10 minutes.

Stir in the garlic, chili powder, cumin, oregano, sugar and salt and cook until fragrant, 30 seconds to 1 minute. Add the tomato sauce and chicken stock and stir to combine. Nestle in the chicken. Bring the mixture to a simmer.

Reduce heat to low and simmer for 15 minutes until the sauce has thickened slightly. Remove the chicken and place in a bowl. (Optional but recommended: Carefully pour the sauce into a blender and blend until smooth.) Season the sauce with a touch more salt, if necessary and set aside.

Preheat the oven to 400F. Lightly grease a 9x13 baking dish.

Shred the chicken into bite-sized pieces. Add 1 cup of the sharp cheddar cheese, 1 cup of the Monterey jack cheese, the cilantro and the juice of 1 lime to the chicken. Mix to combine. (Set aside the rest of the cheese for topping the enchiladas.)

Stack the tortillas on a plate and cover with plastic wrap or damp paper towels. Microwave on high until warm and pliable, 20-30 seconds.

Scoop ⅓ cup of the chicken mixture on top of a tortilla and press it evenly down the middle. (You'll portion the filling to make 12 enchiladas.) Tightly roll each tortilla and lay seam-side down in the baking dish. Repeat with the remaining tortillas.

Pour the sauce over the enchiladas and top with the remaining cheese. Cover the baking dish tightly with foil. Bake covered for 20-25 minutes. Remove the foil and continue to bake for another 5-10 minutes until golden and bubbly. Remove from the oven and let stand for 10 minutes before serving. Serve with your favorite toppings and enjoy!