Sauce: Heat the butter in a pan. Stir in the flour and cook for 1 minute.

Stir in the hot milk and cook for 3 minutes. Add the cream and stir through.

Season to taste with salt and pepper. Keep aside.

Spinach: Heat the butter over low heat in a pan and sauté the onion and garlic for 3-4 minutes, or until soft.

Finely chop the spinach and stir into the onion mixture in the pan.

Stir-fry for 1 minute. Add the feta cheese and white sauce and stir thoroughly.

Serve hot.