In a frying pan, over medium heat, melt 3 tbls. butter, add mushrooms and cook until limp. Stir in crushed saltines then press mixture evenly over bottom and sides of greased pie plate to form a crust.
In the same frying pan, over medium heat, melt 2 tbls. butter, add onion and cook until limp. Spread onions over mushroom crust, sprinkle evenly with shredded cheese.
In a blender whirl cottage cheese, eggs and cayenne until smooth. Pour into crust and sprinkle with paprika.