Step 2
While chicken is roasting, heat 2 tablespoons oil in a large saucepan over medium. Add carrots, onion, and thyme; season with salt and pepper, and cook until carrots are crisp-tender, 8 to 10 minutes. Add flour, and cook, stirring 1 minute. Gradually add milk, stirring until smooth. Cook, stirring occasionally until mixture comes to a simmer and thickens.