Heat the olive oil in a large saucepan over medium heat. Add the onion and shallot and saute for 3-4 minutes, until the onions begin to turn tender. Stir in the garlic and cook for an additional 3 minutes. Add the arborio rice to the saucepan and cook, stirring constantly, for 2 minutes. Lower heat to medium-low, then stir in the white wine, lemon juice, and lemon zest, and cook, stirring constantly, until the liquid is absorbed. While stirring, pour in 1 cup of the vegetable stock. Cook, stirring, until the liquid is absorbed. Add stock in 1/2 cup increments, stirring each time until the liquid is absorbed. (Note that you may not need all 5 cups to cook the rice.) When the rice is tender, stir in the nutritional yeast and thyme. Taste, and add more salt and pepper as needed. Fold in the blanched asparagus and cook until heated through.