Over medium heat, heat oil with 2 tbsp. of butter in a deep pan until butter has melted. Stir in onion and sundried tomatoes, stirring for five minutes until the onions are soft. Do not brown. Lower the heat, add the rice and mix to coat in the oil and butter. Cook and stir for two-three minutes until the grains of rice are translucent. Add the wine, stirring constantly, until it has reduced. Add the stock gradually, one ladleful at a time. Stir constantly and add more ladles as the rice absorbs each ladle. Raise the heat to medium so the liquid bubbles. Cook for 20 minutes, or until all the liquid is absorbed. Season to taste.
While the risotto is cooking, cut asparagus into one inch pieces. Gently fold the asparagus into the risotto during the last five minutes of cooking time. Remove from heat and add the rest of the butter. Stir in Parmigiano until it melts. Garnish with whole asparagus spears and sprinkle with lemon rind.