Clean the mussels thoroughly with water.

Put a little oil in a large deep frying pan, so that it covers the bottom.

When the oil heats, add the onion finely chopped as well as the garlic, cook a little until golden and then add the mussels.

Add 1/2 cup water, cover the frying pan with a lid and let the mussels cook, so that they open up. If they don't open but remain closed it means that they are not fresh and they are dangerous to eat, so take care!

When you see the mussels open up, add the finely chopped pepper, let everything cook for a couple of minutes and then add the tomato paste.

Stir well from time to time, then add salt, pepper and cinnamon and after you leave the ingredients to cook and combine for 10 minutes take pieces of feta cheese and crumble them into the skillet.

Stir well and constantly, for five minutes, then remove from heat and serve!