Finely chop the red onion.
Discard the tops of the koussa and grate them. Place them inside a thin kitchen towel and squeeze the juices all out really well. When you’re done squeezing, squeeze again for good measure, until no liquids comes out.
In a large bowl, add the onion, the squeezed koussa, the crumbled feta, eggs, flour, chopped herbs, smashed garlic, salt, and spices. Mix them well.
In a large nonstick pan, heat some olive oil and cook the fritters in batches of three or four, flipping them only once when they become golden on one side.
Serve with bread and twist of lemon.