Pre-heat oven to 375 degrees.Heat olive oil in a heavy soup pot over medium heat. Add onion and garlic and sauté until soft, about 5 minutes.Add broccoli florets and stir for another 2 minutes.Add stock and bring to boil, reduce to a simmer and let cook for about 10 minutes. Turn off heat and let cool.Meanwhile, line a baking sheet with parchment paper.Cut the bread into 1 inch slices and remove crust. Cut slices into 1 inch cubes and place on baking sheet. Drizzle olive oil and salt over bread pieces and toss to coat well using your hands.Place baking sheet in oven and cook for about 15 minutes until golden brown, shaking sheet half way through to flip croutons.Place the cooled soup into a high powered blender and mix until smooth. Pour into a clean pot, add cheese, salt and pepper.Ladle into soup bowls and top with grated cheese and croutons.