Peel the asparagus, chop off the ends, and cut the tips to a length of approx. 8-10 cm. Dice the remainder finely and set aside. Bring the asparagus stock to a gentle simmer and cook the tips for 3-5 minutes until just tender. Rinse with cold water, cut in half if necessary, and set aside.
Sauté the finely chopped onion in butter. Add the rice, and toast while stirring. Deglaze with white wine and continue cooking until absorbed.
Add just enough asparagus stock to cover the rice. Continue adding a little stock at a time, as required, to ensure that it does not burn. Cook for 18-20 minutes on medium heat to an al dente consistency, stirring regularly. Add the diced asparagus 10 minutes before the end of the cooking time.
Stir in the finely diced cheese and the remainder of the butter, and season with salt and pepper. Slice the Speck Alto Adige PGI into thin matchsticks and sauté. Garnish the risotto with the asparagus tips and the speck.