Fry the onion, then add the chopped garlic clove and the spinach leaves. Pour in the canned tomatoes and briefly bring to the boil until the spinach leaves are cooked through.
In the meantime, cook the pasta.
Season the sauce with the mentioned spices and add the cream and the feta cubes just before serving. The feta cubes should no longer cook, just warm up so that they don`t completely dissolve in the sauce.