Place in the instant pot with enough water and season with salt and set to sauté and bring to the boils and cook 3/4 or until just soft enough to pierce with a fork - turn off the instant pot
Drain the water and place the potatoes on a tray to cool (pat off any excess water with a paper towel
Now dry the pressure cooker bowl and add half the olive oil. Then turn onto sauté again and cook the onion, garlic, and chorizo stirring for about 5 minutes until the onion goes clear and a bit soft.
Lightly grease the cake tin and line the base and sides with baking paper
Stir in the tomatoes and zucchini (we squeezed the water out by hand fist on the zucchini - season to taste with salt and pepper - Cook about 3-5 minutes
Now Spread the base with potato and little cheese. Then add the Chorizo lay and finally the vegetable layer and then topping with cheese.
Pour in your egg mixture and tap and lightly bang the tin to ensure that the egg mixture gets fully inside.
Wrap the tin completely in tin foil. Also, fold two lengths of foil to make a sling ( see our carrot cake instructions for how to do this in a pressure cooker)
Place the trivet in the bowl and put approximately 2 cups of water to also come to the trivet but not quite.
Lower the wrapped tin into the pressure cooker and cook on high pressure for 45 minutes. Release the pressure using quick release and take care fo the steam.
Dress the Tortilla Pie as you like - we dress it with red pepper and a little cheese.