Heat the olive oil in the pressure cooker over medium heat.
Add the grated onion and sauté until softened and lightly golden.
Add the green beans and potato cubes and continue to sauté for 2–3 minutes.
Season with salt and black pepper and stir well.
Pour in the tomato juice, add the chopped parsley and a little water, then stir everything together.
Secure the pressure cooker lid and cook for 25 minutes from the moment the pressure valve rises