Take a medium size pan, heat olive oil. Add chopped garlic cloves, onion, celery, and cook, stir occasionally for about4-5 minutes until get softened. Now add thyme/parsley, cook, stirring until fragrant come out for at least 15 seconds.
Stir in broccoli, add water and broth(chicken/vegetable), and broccoli. Now bring to a lively simmer over high to medium heat. Now carefully reduce heat to maintain the texture of the lively simmer and let it cook until very tender for about 10 more minutes.
Get a blender to pour the soup in it, and start blending until getting a smooth texture.
In a small saucepan, over medium to low heat melt 3 tbsp butter, stir in all-purpose flour, and gradually add milk. Stir until thick and bubbly texture comes out. Now add the mixture into the blended soup.
Now add salt and ground pepper in it.
Now Garnish with cheese, bacon, and scallion and serve it hot (optional).