I got this one here years and years ago and it's been a family favorite every since.

Chicken Cacciatore by Shopper (Christiane )

I use 5 or 6 chicken breasts ( Half a breast each )
3 tablespoons shortening ( I use light olive oil )
2 medium onions, thinly sliced
2 cloves garlic minced
3 stalks celery chopped
1 can ( 1 pound or 16 oz ) tomatoes - i use the diced ones
1 can ( 8 ounce ) tomato sauce
1/3 minced green pepper
1 teaspoon salt
1/4 black pepper
1/2 teaspoon crushed basil
1 bay leaf
1/4 cup Chianti wine ( if desired )

Brown chicken breasts in hot oil in skillet
Layer onion slices in slow cooker
Put browned ckicken pieces on top of onion slices
Then add remaining ingredients ( i put them all in a bowl first and mix them together and then pour over the chicken breasts)
Cover and cook on Low 6 to 8 hrs ( or High 3- 4 hrs )
Discard bay leaf.
Serve chicken pieces with sauce over buttered spaghetti