Linda Styger, an Organic Valley dairy farmer from Washington State, contributed this hefty, cool-weather soup. In what she calls her "typical, straightforward, farm-style way of cooking," she seasons it only with salt and pepper. But if you like, you can add dried herbs to the white sauce base, or fresh herbs to the finished soup. We also like it with bits of Organic Prairie ham or cooked pork in it.
Make the white sauce base: Melt butter in a heavy soup pot over medium heat. Use a wooden spoon to stir in flour a little at a time, until it is all incorporated and mixture is smooth. Cook, stirring often, 3-4 minutes. Whisk in 4 cups of the milk. Cook, whisking frequently, until mixture is thick and smooth. Reduce heat and cook, stirring often, 5-10 minutes.
Meanwhile, steam potatoes and carrots until tender over simmering water in a covered pot. Add cooked potatoes and carrots to white sauce. Stir in corn and peas. Add additional milk to create desired soup consistency. Season to taste with salt and pepper. Reduce heat to low and cook soup until corn and peas are tender.