Skinny Cream of Broccoli Soup

My kids love broccoli but with less spices. They told me broccoli flavour is good with less spices. To them broccoli is one of the vegetable that taste great even with simple steaming. They have been asking for soup for quite sometime. As I am not a big fan of this vegetable I keep postponing this. Finally I manage to do this  low calorie / low fat version. Everyone in the family loved it. In fact this is so regular now a days at our home
Olive oil - 2 teaspoon
White Onion - 3 tablespoon (cubed)
Garlic - 4-5 pods (finely chopped)
Broccoli - 4 cups (small florets)
Vegetable stock /  water - 4 cups
Slim Milk - 2 cup
all purpose flour / maida - 2 tablespoon
Pepper to taste
Salt to taste
Shredded cheddar - 1 tablespoon (Optional)

In a 6-quart stockpot over medium heat, Add olive oil. When it is hot add Garlic and onion. Fry till it is slight brown color. Add broccoli fry for 30 sec. Add vegetable stock / water and water. 
Cook the broccoli it will be done with in 5-7 min. Switch off the flame and let it cool down. Mix the flour with milk and whisk without any lumps. Keep it aside.
Take the broccoli and onion ( I have filtered the water out. Keep the water for future use) for grinding. Make puree in the food processor or in blendar or in mixie. Heat the stockpot again. Add the water and milk and mix well. 
Bring this mixture to boil. Add broccoli puree.
And mix well. Add salt and pepper. Mix well. Let it boil. Switch it off. 
Serve with shredded cheese (optional) or croutons or bread.