Preheat the oven to 400 degrees Fahrenheit and prepare a casserole dish.
Heat a skillet over medium-high heat and add the olive oil. Cook the minced garlic until fragrant, about 1 minute. Add the shredded chicken and cook until warm. Set aside.
In a bowl combine the sour cream, salsa verde, and half of the chopped cilantro. Season with salt and pepper.
Combine the shredded chicken with half of the salsa verde sauce to make the filling. Divide the filling between the tortillas, roll them up, and place them into the casserole dish.
Spread the remaining sauce over the tortillas and sprinkle with Mexican or cheddar cheese.
Cover the casserole with aluminum foil and bake in the preheated oven for about 15 minutes. Remove the foil and bake for another 10 minutes, until the cheese is melted and lightly golden brown.
Remove the casserole from the oven and garnish it with chopped cilantro and red onions.
