In a large saucepan, cook 1 tablespoon of the butter over moderate heat until it sizzles. Add the cinnamon stick, mussels and white wine, cover and steam until the mussels open, about 2 minutes. Pour the mussels into a large strainer set over a bowl and let cool.
Remove the mussels from their shells and place in a small bowl. Season with pepper and the lemon juice.
Wipe out the saucepan. Add 1 tablespoon of the butter, the chiles and half of the basil and parsley and cook over moderate heat for 1 minute. Add the garlic, tomato paste and the reserved mussel cooking liquid and boil until the sauce has reduced to 1 cup. Remove from the heat and add the mussels.
Dice the remaining 2 tablespoons of butter. Scatter the butter and the feta over the mussels and bring almost to a boil over moderate heat, swirling the pan to melt the butter and feta. Season with salt and pepper. Garnish with the remaining herbs and serve.
Toasted peasant bread rubbed with olive oil and garlic.
Chiles and feta will kill a subtle wine. So, go for a robust white from Greece or Spain.