Chicken with Vegetables and Cheesy Dumplings

Name: Chicken with Vegetables and Cheesy Dumplings
Ingredients: 2 boneless skinless chicken breasts; Kosher salt and freshly ground black pepper; 2 tablespoons olive oil; 4 tablespoons unsalted butter; 8 ounces cremini mushrooms, trimmed and quartered; 2 medium carrots, thinly sliced; 1 leek, light green and white parts halved lengthwise and thinly sliced crosswise; 3/4 cup plus 3 tablespoons all-purpose flour; 2 1/2 cups low-sodium chicken broth; 1/2 small head cauliflower, cut into 1/2-inch florets (about 2 cups); 3 sprigs thyme; One 8-ounce bag Sargento Fine Cut Shredded Sharp Cheddar (2 cups); 3 tablespoons chopped fresh chives; 1 teaspoon baking soda; 1/3 cup milk