1. Lightly oil four 5 to 6 ounce custard cups or baking cups. Choose a baking pan in which the cups fit comfortably. Pour enough water into the pan to fill 1 inch. Place the pan of water (without the cups) on the center rack of the oven. Heat the oven 350 degrees.
2. Drain the artichoke hearts and cut them into quarters. Trim the root end and green parts from the leeks. Split the leeks lengthwise and rinse thoroughly under cold running water to remove sand and grit from between the layers. Slice the leeks 1/2 thick. Squeeze excess moisture from the vegetables by pressing firmly against the sides of the sieve. Transfer to a food processor fitted with the metal blade. Process until finely chopped. With the motor running, add the half and half in a thin, steady stream. Add the egg and cheese and process until blended into the puree. Stir in the lemon juice and season to taste with salt and pepper.
3. Divide the mixture among the prepared cups. Place in the water bath and bake until the centers are firm, about 35 minutes. Remove and cool. Run a thin knife between the sformati and the cups to loosen. Unmold the sformati onto warm plates. Serve warm.Makes 4 servings
Per Serving: 196 Calories (55.9% from fat); 12g Fat (5g Sat, 5g Mono, 1g Poly); 8g Protein; 14g Carbohydrate; 5g Dietary Fiber; 75mg Cholesterol; 477mg Sodium. Food Exchanges: 1/2 Lean Meat; 2 Vegetable; 2 Fat.
Variation: Broccoli and Cauliflower SformatiSubstitute 1 1/2 cups each coarsely chopped cauliflower and broccoli and 1 small onion, peeled and thinly sliced, for the artichoke hearts and leeks.