1/4 cup butter
1/4 cup all-purpose flour
2 cups milk
2 cups chicken stock/broth
1/2 tsp. dried thyme leaves or 1 tsp. fresh thyme leaves
2 medium russet baking potatoes diced (about 2 cups)
2 medium carrots sliced or diced (about 1 1/2 cups)
1 1/4 cup frozen peas
2 cups cooked chicken or turkey diced (about 1 large boneless breast)
In a large pot over medium heat, melt butter. Add flour and stir continuously, cooking for about 1 minute. Start adding the milk a bit at a time, stirring well until smooth before adding more. Once all the milk is added, pour in the chicken stock. Add the diced potatoes, carrots and thyme. Bring soup to a boil, then reduce heat and simmer until potatoes and carrots are tender, about 15-20 minutes, depending on the size of your dice.
Add frozen peas and cooked chicken or turkey. Cook over low heat an additional 10 minutes or so, to cook peas and warm chicken. Taste soup. Add salt and pepper to taste. You may also wish to add a bit more thyme, to taste.
Serve hot, topped with crumbled soda crackers or pie-pastry croutons (pie pastry, cut into small squares or other shapes, then baked off and scattered on top of soup).