1 (9" - 10") pastry shell
1 (12-13 oz.) can tuna, drained & flaked
1 c. shredded Swiss cheese (or cheddar)
1/2 c. chopped onion
3 eggs
1/2 c. milk
1 c. mayonnaise

Bake shell 10 minutes at 375 degrees. In large bowl toss tuna, cheese and onion. Spoon into shell. In bowl mix remaining ingredients and slowly pour over tuna mixture. Bake 50 minutes or until knife comes out clean at 350 degrees.