Set pressure cooker to "sear", add butter, and press "start/stop". When butter is melted, add onions and garlic.
Add the spinach, peas, tomatoes, and vegetable stock. Stir to mix well.
Close and lock lid, set pressure cooker to "steam/veggies", adjust time to 4 minutes, and press "start/stop".
When done, quick release and make sure all pressure is released before opening lid.
Carefully open lid and season with sea salt and fresh ground black pepper. Stir in the lemon zest and lemon juice. Add tortellini and mix well. Serve hot and garnish with Parmesan cheese.
