Preheat oven to 350°. In a small bowl, mix flour and 1/4 teaspoon salt; cut in 1/2 cup butter until crumbly. Gradually add cottage cheese, tossing with a fork until dough holds together when pressed. Shape into a disk., On a floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim crust to 1/2 in. beyond rim of plate; flute edge., In large skillet, heat remaining 3 tablespoons butter over medium heat. Add onions; cook and stir until golden brown. Stir in Canadian bacon, pepper and remaining 1/2 teaspoon salt. Remove from heat; add eggs and cheddar cheese. Pour into crust., Bake on a lower oven rack 40-45 minutes or until a knife inserted in the center comes out clean. Let stand 10 minutes before cutting.