Celery and Potato Soup

Because sometimes you just have a ton of celery in your fridge.

1 TBSP olive oil
3 cups celery (sliced)
2 cups potatoes (diced)
1 cup onion (chopped)
1 tsp garlic (minced)
2 cans chicken broth
1/2 cup water
1/2 milk
1 TBSP Dijon mustard

Heat oil in large saucepan. Add celery, potatoes, onion, and garlic. Cook about 5 minutes. Add broth and bring to a boil. Reduce heat and simmer, uncovered, about 10 minutes or until potatoes are tender. Blend half the soup in a food processor and poor into the remaining mixture. Stir in milk, water, and Dijon. Heat 1 to 2 minutes. Sprinkle with cheese if desired.