Wash the asparagus and cut off the woody ends generously. Cut the asparagus into bite-sized pieces. Clean and slice the porcini mushrooms. Peel, wash and finely dice the carrot. Peel onion and dice very finely.
Dissolve the stock in a good 1 l boiling water and keep it hot. Heat the oil in a large pot. Steam onion and vegetables for about 5 minutes while stirring. Add rice and roast for 1-2 minutes while stirring until the rice grains start to "crackle".
Slowly add some hot stock and stir from time to time. As soon as the rice has absorbed the broth, add broth again and again. After about 9 minutes cooking time, stir in frozen peas. Simmer rice open at low heat for another 10 minutes.
Keep stirring it so that nothing sticks. Add some stock until the rice is creamy but still al dente.
Grate parmesan. Fold parmesan and butter into the finished risotto. Season to taste with salt and pepper. Let it rest for 1 minute and serve hot.