• 1 leek, white and pale green parts only
• Coarse sea salt
• 3 medium tomatoes
• 1 1/4 pounds fresh fava beans in pod, shelled, or 1 cup frozen double-peeled fava beans, thawed
• Extra-virgin olive oil
• Freshly ground black pepper
• 1 cup shelled fresh peas (1 to 1 1/2 pounds in pods) or frozen peas
• 1 large carrot, finely chopped
• 7 ounces robiola cheese, softened at room temperature, cut into small pieces
• 4 ounces mascarpone cheese (1/2 cup), at room temperature
• 12 large zucchini blossoms, stems and pistils removed
• Good quality balsamic vinegar

Special Equipment: a 10-inch disposable pastry bag or sealable plastic bag
 

Cut leek in half lengthwise, then cut crosswise into 1/4-inch pieces and wash. 

Bring a large saucepan of salted water to boil. Drop tomatoes into water and boil 30 seconds. Using a slotted spoon, remove tomatoes. Peel, seed, and cut into 1-inch pieces. Transfer to a bowl.

Cook fava beans in the same pot of boiling water until tender, about 5 minutes. Using a slotted spoon, transfer to a colander. Run under cold water for 1 minute to stop cooking, then pat dry with paper towels and add to bowl with tomatoes. Drizzle with oil, and season with salt and pepper.

Cook leeks, peas and carrot in the same pot of boiling water until tender, about 5 minutes. Drain and run under cold water for 1 minute to stop cooking. Transfer to a large bowl.

Add robiola, mascarpone and generous pinch salt and pepper to leek mixture; stir together to combine. Transfer cheese mixture to pastry bag. Snip a 1/3-inch opening and pipe filling into blossoms. Using your fingers, gently press petals around filling. Chill stuffed flowers until filling is just set, about 15 minutes.

Divide tomato mixture among 4 serving plates. Arrange blossoms on top. Drizzle with oil and vinegar and season with salt and pepper.