Broccoli Soup

3 cups broccoli, cut into bite sized pieces
1 onion chopped into small pieces
1 small russet potato, peeled and diced very small
1 litre vegetable stock
1/2 cup red lentils
2 cups skim milk
Salt and Pepper
Shredded cheddar cheese to top soup

Bring stock to a boil. Add broccoli, onion, potato and lentils. Cook until all vegetables are tender. Once cooked, add milk, and salt and pepper to taste. Top with cheddar cheese when serving.