Peel cucumber, cut in half lengthwise and scrape out the seeds. Slice into 1 cm (approximately 1/2 inch) slices. Trim snow peas and halve lengthwise. Rinse dill, shake dry, pluck off the fronds and chop coarsely.
Heat the chicken stock in a saucepan.
Chop onion and garlic. Heat oil in a pan and sauté onion and garlic until soft.
Add rice and sauté briefly. Deglaze with white wine. When the rice has absorbed the wine, Ladle in about 150 ml (approximately 3/4 cup) of hot stock and cook, stirring frequently, until almost all liquid is absorbed. Continue to add stock in this manner and cook until rice is al dente, about 20 minutes, stirring frequently. Season with salt and pepper. About 5 minutes before end of cooking, add cucumber, snow peas, dill, 1 tablespoon butter and the Parmesan.
Clean mushrooms, fry in butter, season with salt and pepper and sprinkle over the risotto before serving.