Bring 3-4 l salted water (1 teaspoon salt per litre) to the boil. Pour 1⁄4 l boiling water over the peas and let them stand for about 2 minutes. Cook pasta in boiling salted water according to package instructions.
Wash mint, shake dry and pluck off leaves. Drain the noodles and collect 50 ml of noodle water. Put the noodles back into the pot. Ricotta, 3⁄4 Puree peas, mint and pasta water in a tall beaker with a hand blender.
Season to taste with salt, pepper and lemon juice. Mix the ricotta sauce with the pasta. Season again.
Cut cress from the bed. Carefully wash the sprouts and drain them well. Grate the parmesan and pluck the ham. Arrange pasta with remaining peas and ham. Sprinkle with parmesan, cress and sprouts.