Cheesy Baked Salsa Chicken

4 boneless skinless chicken breasts
2 Tbs. canola oil
2 large onions, thinly sliced
3/4 cup thick and chunky salsa of your choice
1 cup sour cream
1 cup shredded cheddar cheese
1 cup shredded jack cheese
(Reserve 1/2 cup cheeses to garnish)
Optional garnishes:
diced jalapenos, green chile's, and sliced black olives on top before baking.

Heat oven to 350. Season chicken with salt and pepper and pepper and
lightly brown in oil. Set aside. Saute onion just until soft. Mix
cheeses, sour cream and salsa together. Spray a 9x13 baking pan with
Pam and arrange chicken breasts, then top with onions. Pour sour cream
mixture over and top with remaining cheese. Bake uncovered for 30
minutes.