For the spinach, place frozen spinach in a large frying pan on a high heat. Cover and cook for a few minutes. Then stir and keep cooking until the spinach is hot and the excess liquid has evaporated. Divide between two plates or flat bowls.
Rinse out the pan and get it back on a high heat. Add a little oil and the meat and cook, stirring until the meat is no longer pink but don't worry about browning it too much.
Add the onion powder (if using) and tomato passata and 1/4 teaspoon salt. Bring to the boil and simmer to reduce for a few minutes.
Pile the meat sauce on top of the spinach. Finish by dolloping the yoghurt on top and scattering over the olives.