Ham and Potato Soup

Made this up for dinner tonight.  It was so delicious I thought I'd better write down the recipe before I forget what I put in it!

Ham and Potato Soup
Serves 4 - 6

2 T. butter
1 T. olive oil
1 large onion, chopped
4 c. chicken broth
5 cloves garlic, minced
1 large potato (or equivalent - I used six baby potatoes), diced
2 c. diced ham
1 tsp. dried thyme
1 tsp. dried dill weed
salt and pepper to taste
2 T. cornstarch, mixed with 2 T. cold water until smooth
1/2 cup half and half

In a three-quart pot, saute the onions in the butter and olive oil until they just start to brown.  Add chicken broth, potato, ham and seasonings.  Bring to a boil; reduce heat to low and simmer 15 minutes, or until potatoes are soft.  Stir in cornstarch mixture; turn temperature back up to medium-high.  Cook and stir until thickened.  Add half and half.  Reduce heat to low and cook five minutes more.