Heat 1 Tbsp olive oil over medium heat in a large pot. Add mushrooms and cook until they begin to sweat (release their moisture), about 5 minutes. Remove mushrooms from pan.
Heat remaining 1 Tbsp olive oil in the pan over medium heat. Add shallots and garlic, cooking until shallots are translucent and soft, about 3 minutes.
Add dry rice and cook, stirring frequently, for about 2 minutes, or until the rice is slightly opaque on the outside but uncooked on the inside.
Add wine to the pot and simmer until wine has completely been absorbed.
Slowly add the vegetable broth, adding ½ cup at a time. Wait until broth has completely absorbed before adding another ½ cup, continuing this process until rice is cooked through. Begin tasting the rice after 10 minutes or so. Once it is al dente (a little bit chewy), stop adding broth (you may not need the full amount).
Stir in parmesan, butter, and mushrooms. Taste and add salt and pepper to suit your liking.