Preheat oven to 350 degrees.
In a medium bowl combine salsa, cream, and sour cream.
In a second bowl mix chicken, garlic, and oregano, plus 3/4 cup of the sauce and stir to combine.
In a 9x13 baking dish, pour about 1/2 cup of the sauce. Place 6 tortillas in pan, flipping to coat both sides of each tortilla.
Pour the chicken mixture over the tortilla and spread evenly around the pan.
Evenly sprinkle all of the cheese over the chicken.
Dip each of the remaining tortillas in the remaining sauce and place on top of the cheese.
Pour the remaining sauce over the casserole and spread to evenly coat.
Bake for 40-45 minutes, or until the sauce is bubbling.