1.5 lb boneless, skinless chicken breasts, cut into 1-inch pieces
8 red potatoes, peeled and sliced
2.5 cups broccoli, roughly chopped
½ small white onion, thinly sliced
2.5 cups low sodium chicken broth
1.5 cups milk
¾ cups flour
1 clove garlic
2 tablespoons Dijon mustard (I use Maille)
zest from 1 lemon
¼ cup grated Parmesan cheese, plus more for garnish (if desired)
2 teaspoons salt, divided
2 teaspoons pepper, divided
fresh flat leaf parsley for garnish (if desired)
butter or nonstick cooking spray (for greasing your casserole pan)
Preheat the oven to 425 degrees. Grease a 9x13 with butter or non-stick cooking spray and set aside.
Bring the chicken broth and 1 cup milk to a low boil in a saucepan. Whisk the other ½ cup milk with the flour, 1 teaspoon salt and 1 teaspoon pepper; add the mixture to the boiling liquid and whisk until a creamy sauce forms. Add the Parmesan cheese and lemon zest and whisk thoroughly. Remove from heat and let cool slightly.
In a large mixing bowl, add the chicken, onions, garlic, 1 teaspoon, 1 teaspoon pepper, broccoli and potatoes and toss gently to combine. Slowly pour the creamy sauce over the chicken mixture and toss again gently so that the sauce is coating the vegetables and meat.
Pour the chicken mixture into the greased 9x13 pan. Cover tightly with aluminum foil and bake at least 1 hour until the potatoes are tender and the casserole is bubbly.Carefully remove the foil and switch your oven to the "broil" setting and broil the casserole for 2-3 minutes until the top is browned and slightly crispy, watching carefully to make sure it doesn't burn. Garnish with more Parmesan cheese, salt, pepper and freshly chopped parsley if desired.
Recipe by Grits and Chopsticks at https://www.gritsandchopsticks.com/the-gravy-train/2015/12/lemon-chicken-broccoli-casserole-maille-mustard.html