Wash the asparagus, cut off the woody ends. Cook the asparagus in 1 litre of boiling, slightly salted water for about 8 minutes. Remove asparagus from the boiling water and drain. Stir the vegetable stock into the asparagus water and bring to the boil.
Heat 1 tablespoon of olive oil in a saucepan. Add rice and heat for 2 minutes while stirring. Reduce heat. Gradually add stock to the rice. Stir again and again. Cook the rice for about 20 minutes.
Cut the asparagus into pieces. Grate parmesan. Clean and halve the mushrooms. Peel garlic and chop finely. Heat 1 tablespoon of olive oil in a frying pan. Sauté the mushrooms in it. Add garlic.
Season with salt and pepper. Add asparagus, Parmesan cheese (except something to sprinkle) and mushrooms to the rice. Heat the vegetables in it. Season with salt, lemon juice and pepper. Arrange risotto with ham slices.
Sprinkle with the rest of parmesan and garnish with chervil leaves.