Heat the olive oil in the pressure cooker pot over medium-high heat. Add the onions and sauté until they are translucent for about 2 minutes. Add the garlic and sauté for another minute.
Add the lemon zest, cumin, and spinach. Cook until the spinach softens, about 1 more minute.
Add the rice, vegetable stock, 1 tablespoon of dill, salt, and pepper and stir to mix. Close and lock the pressure cooker lid and bring to HIGH pressure.
Once pressure is reached, reduce the heat to medium low and cook for 10 minutes at HIGH pressure.
Once the cooking time is done, release the pressure and remove the lid. Leave the pot on low-medium heat and stir for 2-3 more minutes.
Add the lemon juice and the rest of the fresh dill. Garnish with feta before serving.