1 cup flour
2 teaspoons sugar
1/4 teaspoon salt
1/4 cup unsalted butter, cut into pieces
3 tablespoons sour cream
4 cups packed Swiss chard or spinach leaves, chopped
1/4 teaspoon sugar
3 egg whites
3/4 cup milk
1/4 cup cottage cheese
1 tablespoon flour
1 cup shredded Monterey jack cheese
For the crust: In a medium bowl, combine flour, sugar, and salt. With a pastry blender or two knives, cut in butter until mixture resembles coarse meal. Add the sour cream and stir until just combined. Flatten, wrap in plastic, and refrigerate for at least one hour.
Preheat the oven to 375 F. On a lightly floured surface, roll the dough out to a 13-in round. Fit the dough into a 10-in tart pan. With a fork, prick the bottom of the shell in several places. Press down and line with foil. Bake for 15 minutes or until edges begin to brown. Cool on a wire rack.
For the filling: Rinse the chard and place it, with water still clinging to it, in a large skillet over medium heat. Sprinkle with sugar, cover, and cook for 5 minutes. Uncover and cook for 5 minutes or until liquid has evaporated. Set aside.
Combine the whole eggs, egg whites, milk, cottage cheese, and flour, and process until smooth. Transfer to a medium bowl and stir in the shredded cheese.
Place the tart shell on a baking sheet with sides. Spread the chard over the bottom of the tart shell. Pour the egg mixture over and bake for 30 minutes or until the custard is set. Serve warm.