Heat olive oil in a pressure cooker set to Sauté. Cook and stir rice, onion, and garlic in oil until onion is translucent, about 4 minutes. Pour vegetable stock into the cooker and stir to break any large clumps of rice into grains; add fresh mushrooms, shiitake mushrooms, nutritional yeast, miso paste, white wine, ½ teaspoon salt, and pepper. Seal the lid on the cooker and cook on High Pressure for 10 minutes. Relieve pressure through the quick-release valve. Stir the risotto and let cool for 5 minutes; garnish with parsley to serve.