Combine flour and salt. Stir in shredded cheddar; cut in butter with pastry blender until mixture is crumbly. Sprinkle cold water one teaspoon at a time over surface. Stir with a fork until dry ingredients are moistened. Shape into a ball; chill one hour. Shape into 36 balls. Place in greased miniature muffin pans, shaping into a shell in pans.

Cook spinach according to package directions; drain. Press between paper towels to remove excess moisture. Combine spinach, cottage cheese, and remaining ingredients; stir well. Spoon mixture evenly into prepared shells. Bake at 400F for 25 to 27 minutes, until golden. Cool for 2 minutes. Loosen sides of tarts with a knife, remove and serve warm.