Preheat oven to 300°F

Sprinkle chicken thighs with salt and pepper

Chop onion

Brown chicken thighs in skillet quickly on both sides until golden brown, about 2 minutes per side

Remove to a separate plate

Pour off all but 1 tablespoon grease/oil

Add chopped onions and garlic to pan and stir around to cook, about 2 to 3 minutes

Pour in marinara sauce and stir to heat

Add chicken thighs back into sauce

Cover and place in preheated oven for 1 hour 30 minutes

Cook pasta according to package instructions

Serve 1 chicken thigh with sauce over pasta, adding more marinara if needed

Sprinkle with Parmesan

Serve