1hr 5min · 8 servings Ingredients • 1 tablespoon butter ½ onion, chopped ¼ cup melted butter ¼ cup flour 2 cups milk 2 cups chicken stock 1 ½ cups coarsely chopped broccoli florets 1 cup matchstick-cut carrots 1 stalk celery, thinly sliced 2 ½ cups shredded sharp Cheddar cheese salt and ground black pepper to taste Instructions Step 1 Melt 1 tablespoon butter in a skillet over medium-high heat. Saute onion in hot butter until translucent, about 5 minutes. Set aside. Step 2 Whisk 1/4 cup melted butter and flour together in a large saucepan over medium-low heat. Continue to whisk and cook , adding 1 to 2 tablespoons of milk if necessary to keep the flour from burning, 3 to 4 minutes. Step 3 Gradually pour milk into flour mixture while whisking constantly. Stir chicken s