Fry the onions well in a pan with oil. Add thawed mussels and fry briefly. Deglaze everything with the white wine and simmer briefly.
Now add the tomato cubes, press or finely chop the garlic through a press and chop the chilli pepper and add it to the pan as well. Mix the vegetable broth with the cornstarch and pour the cremefine into the mussel pan. Bring to the boil and simmer on a low flame for 10 minutes.
Finally, finely crumble the feta and add it.
Melt the cheese and season with salt, lemon pepper, paprika powder, garlic powder and possibly Vegeta.