Garlicky Chicken Casserole

I found this in the Gooseberry Patch Best-Ever Casseroles cookbook and I am posting for safekeeping. It was originally submitted by Shellye McDaniel of Texarkana, TX and she describes it as a "low-carb variation of the chicken enchilada casserole...minus the tortillas!" I will adjust cooking times and methods after I make it.

• Ready In: 40 mins
• Serves: 4-6

Ingredients

• 1⁄2 cup onion, chopped
• 2  garlic cloves, pressed
• 2  tablespoons olive oil
• 2 (12 ounce) cans chicken, drained (or use cooked and shredded chicken, probably about 2 large breasts)
• 10 3⁄4 ounces  cream of mushroom soup
• 10  ounces rotel, drained
• 4 -6  tablespoons  whipping cream
• 1⁄2 cup  shredded cheddar cheese
•  salt and pepper
•  shredded cheddar cheese (garnish)
•  sour cream (garnish)

Directions

1. Preheat oven to 350.
2. In a skillet over medium heat, saute onion and garlic in oil until onion is translucent.
3. Combine the onion mixture and remaining ingredients in a large mixing bowl; stir well.
4. Pour mixture into a lightly greased 13x9" baking dish.
5. Bake for 20-25 minutes.
6. Garnish as desired.