Separate and clean leeks - cut green and white parts into 1/2 inch pieces. Peel potatoes and dice. Sauté potatoes and leeks in olive oil for 3-4 minutes. Add water and bouillon cubes and pepper. Bring to boil - decrease or lower heat and simmer 20-30 minutes until vegetables are tender. Cool soup - blend 1/2 soup in blender if desired. Put back into pan. Add milk and heat - do not boil. Serve with Cheddar cheese over top and garlic bread.