- In a food processor, combine the flour, baking powder, and salt. Add the butter and pulse a few seconds at a time, until the mixture is the size of peas. Add the egg and vinegar and pulse again until the dough just begins to form. Remove the dough from the processor and form into a disc with your hands.
- On a floured work surface, roll out the dough into a 3-mm (1/8-inch) thick rectangle. Fit the dough into a 33 x 10 cm (13 x 4-inch) rectangular pie plate with a removable bottom. Refrigerate the while preparing the filling.
- With the rack in the middle position, preheat the oven to 200 °C (400 °F).
- In a saucepan, sauté the leeks in the butter until tender. In a bowl, combine the eggs and sour cream. Add the leeks and stir well. Season with salt and pepper.
- Spoon into the crust and bake for 35 to 40 minutes or until pastry is golden brown.
Calf’s Liver Salad
- Place the liver cubes in a sieve. Rinse under cold water, drain and pat dry with paper towel.
- In a non-stick skillet over high heat, brown the liver on all sides in the butter. Season with salt and pepper. Add the shallot and cook until browned. Add the honey and vinegar and simmer for 1 minute. Set aside.
- Cut the tart into six pieces and place in the centre of each plate. Spoon the liver salad on top of each slice, topping with the lettuce. Drizzle with a little olive oil.