Mix whole wheat flour with the milk and bring to the boil with the bay leaf, stirring constantly. Let the sauce soak. Remove the bay leaf and season the sauce with sea salt, pepper and nutmeg.
Boil spaghetti (whole grain) in vegetable stock, rinse in cold water and season with sea salt.
Steam the onion cubes and garlic in the olive oil until translucent, add the tomato paste, herbs and spices and bring to the boil. Then add the tomato cubes, mix the whole thing with the drained, seasoned spaghetti and place in a greased baking dish. Spread the broccoli (already blanched) on top, cover with the white sauce and sprinkle with the cheese.
Bake the casserole in a preheated oven at 225 degrees for approx. 5 - 10 minutes.