1 lg. can chicken (don't drain)
1 (12 oz.) pkg. spaghetti (cooked and drained)
1/2 c. onion sauteed in 1/2 stick butter
1 can mushroom soup
1 can celery soup
1 lg. jar Cheez Whiz (or Velveeta)
1 can Rotel

Mix all ingredients. Bake 30 minutes at 375 degrees.