2 garlic cloves, finely chopped
Juice of 1/2 lemon
Heat the oil in a large heavy saucepan over medium heat. Add the shallots, garlic, and thyme, and sauté for 2 minutes, or until the shallots are tender but not browned. Add the rice and sauté for 30 seconds to coat with the oil. Stir in the wine and cook for 3 minutes,or until it is absorbed.
Add 3/4 cup of the hot vegetable stock and cook, stirring constantly, until it has absorbed. Continue adding the hot stock, 3/4 cup at a time, stirring until each addition has been absorbed, for about 22 minutes, or until the rice is al dente (the center of each grain of rice should still be slightly firm).
Add the asparagus and continue to cook for 2 minutes. Discard the thyme stems (the thyme leaves should have fallen off the stems and into the risotto). Remove the risotto from the heat, and add the butter, grated Parmigiano-Reggiano, and mascarpone cheese. Stir until the butter has melted. Stir in the parsley, mint, and lemon juice, and season the risotto generously with salt and pepper.
Divide the risotto among 4 warmed serving bowls. Garnish with the shaved Parmigiano-Reggiano, and serve.