Heat the milk in a small saucepan. Bring 7 cups of water to a boil in a large pot. Cook the 3 cups of broccoli florets until just tender, then cool in water. Divide between 2 individual dishes. Add the remaining broccoli to the pot and cook. Set aside a few pieces for garnish. In a large pot, heat the olive oil and sauté the garlic and onion. Add the celery and sauté. Add the butter and let it melt.

Stir in the flour and cook over low heat for a few minutes, stirring. Gradually pour in the hot milk, whisking constantly to prevent lumps. Season the soup with thyme, oregano, parsley, and pepper. Blend the mixture and add 1 1/2 cups of the cream sauce to the broccoli in the dishes. Sprinkle with Parmesan cheese. Place the dishes in the oven to brown the broccoli while you finish the soup.

Blend the broccoli with the liquid and add it back to the soup in the pot, stirring well. Adjust with more milk or water if you want a lighter soup. Bring to a boil, reduce the heat, and simmer gently for about 15-20 minutes. For the croutons, toss the bread cubes with olive oil and herbs. Toast in the oven until golden. Serve the soup garnished with a little broccoli and croutons.