New England Potato Soup

2 tablespoons butter

1 onion, chopped

1 celery rib, thinly sliced

2 (14.5 ounce) cans chicken broth

5 red potatoes, peeled and cubed

½ teaspoon salt

½ teaspoon dried rosemary, crushed

½ teaspoon dried thyme

⅛ teaspoon ground black pepper

⅓ cup all-purpose flour

½ cup milk

1 ½ cups cubed fully-cooked ham

1 cup frozen peas

2 cups milk

Heat butter in a saucepan over medium heat; cook and stir onion and celery until tender, about 10 minutes. Add broth, potatoes, salt, rosemary, thyme, and black pepper; stir to combine. Bring to a boil, reduce heat, and simmer until potatoes are tender, 15 to 20 minutes.

Whisk flour and 1/2 cup milk together in a bowl until smooth; gradually stir into soup. Bring to a boil, stirring occasionally, until combined, 2 minutes. Stir in ham, peas, and remaining 2 cups milk; cook until heated through, about 5 minutes.