Spaghetti with White Clam Sauce

1 medium onion, chopped
2 cloves garlic, minced
½ cup butter
½ cup oil
¼ cup parsley
½ lb. mushrooms, sliced
juice of 1 lemon
½ cup white wine
1 cans (10 oz. each) baby clams with broth
1 lb. thin spaghetti, cooked
Parmesan cheese

Saute onion and garlic in butter and oil in skillet. Add parsley and mushrooms. Cook until vegetables are tender. Add lemon juice and wine. Stir clams into sauce.