Blueberry Blintzes

Combine in a blender or food processor until smooth: flour, milk, eggs, butter, sugar and salt. Pour the batter into a pitcher or other container with a pouring lip. Cover with plastic wrap and let stand at room temperature for 30 minutes, or refrigerate up to 2 days. Heat a medium nonstick pan over medium to medium-high heat. Melt 1 teaspoon butter in the pan and swirl it around to coat the surface of the skillet. You will need to regrease the pan after cooking each blintz. Use 3 tablespoons batter for each blintz, but do not turn the blintzes. Instead, cook until the top is dry and set and the underside is golden. Meanwhile, combine in a medium saucepan: blueberries, zest and juice lemon, sugar and cinnamon. Bring to a boil over medium heat, stirring constantly, then continue to boil until the mixture is the consistency of jam. Add blueberries and cook and stir for 1 minute. Transfer to a bowl and let cool to room temperature. Spoon 2 generous tablespoons of the filling onto the center of the unbrowned side of each blintz. Fold the sides of each blintz around the filling to form a rectangular package. (The filled blintzes can be wrapped airtight and frozen for up to 1 month.) Heat in a large skillet, preferably nonstick, over medium heat until the butter is melted and the bubbles have subsided: butter and vegetable oil. Add the blintzes, seam side down, to the pan and cook, turning once, until golden brown on both sides. Transfer the blintzes to paper towels to drain briefly. Serve immediately.