4 lg. chicken breasts
1/4 c. chopped onion
1 clove garlic, minced
2 tbsp. butter
1 (16 oz.) can tomatoes, cut up
2 (8 oz.) cans tomato sauce
1/4 c. chopped green chilies
1 tsp. sugar
1 tsp. ground cumin
1/2 tsp. salt
1/2 tsp. dried oregano, crushed
1/2 tsp. dried basil, crushed
12 corn tortillas
2 1/2 c. shredded Monterey Jack cheese
3/4 c. sour cream