Preheat oven to 350°F. Combine cheese, butter, and salt in a large bowl. Mix in the flour and add ice water, one tbsp at a time. Add more water if dough is too dry. Separate dough into two halves. Wrap in parchment paper and chill for 30 minutes. Roll out dough through pasta roller to 1/8 inch. Cut into 1 inch x 1 inch squares. Poke a hole in the middle with a tooth pick. Sprinkle with sea salt. Place on parchment lined baking sheet and bake for 13 minutes.