1 c. sour cream
4 garlic cloves, pressed
1/2 c. melted butter
1 c. mayonnaise
1/4 c. lemon juice
1/2 c. chopped fresh dill

Cover grill with foil. Place tuna or swordfish steaks on grill, spread sauce on one side. Cook fish about 4 minutes. Flip over, spread sauce on other side. Continue cooking until fish flakes - do not overcook. Serve with extra sauce on side (sauce should be warm).