Go Back
–+ servings
Chicken and Mashed Potato Casserole with Creamy Leeks and Mushrooms

Chicken and Mashed Potato Casserole with Creamy Leeks and Mushrooms

Print Recipe Pin Recipe
Prep Time 20 minutes
Cook Time 50 minutes
Course Dinner, Entree, Main Course
Cuisine American
Servings 4

Equipment

  • 1 8" x 11.5" baking dish

Ingredients
  

Main Ingredients:

  • 2 tbsp olive oil
  • 2 tbsp butter
  • 4 thin chicken breasts - or 2 chicken breasts sliced in half horizontally
  • 4-5 large russet potatoes - peel and cut into chunks
  • 1 leek - white & light green parts only, slice thinly then wash thoroughly
  • 1 yellow onion - diced
  • 8 oz baby belle mushrooms - thinly sliced
  • 2 big handful spinach - cut into smaller pieces
  • 3 cup shredded mozzarella cheese
  • 1/4 cup shredded parmesan cheese

Chicken Seasoning:

  • 1 tsp salt
  • 1 tsp garlic powder
  • 1 tsp paprika
  • 1/2 tsp black pepper
  • 1 tsp Italian seasoning

Veggies Seasoning & Sauce:

  • 1 tsp onions salt - I’m using Trader Joe’s
  • 1/2 tsp black pepper
  • 1/2 tsp paprika
  • 2 tsp soy sauce
  • 2 tsp chicken bouillon
  • 1-2 tsp Calabrian chili
  • 1 cup heavy cream
  • 1/4 cup water

Mashed Potato Seasoning:

  • 4 tbsp butter
  • 1 tsp salt
  • 1/2 tsp black pepper
  • 3/4 cup milk
  • 1/2 cup heavy cream

Instructions
 

Boil and Mash the Potatoes:

  • Boil the potatoes in a large pot of water until they’re fork tender (around 20 minutes). Drain the water completely, then mash the potatoes using a potato masher.
  • Add the butter, salt, black pepper, milk, and heavy cream. Continue mashing until the potatoes are smooth and creamy. If needed, add a little more milk or heavy cream until you reach your desired consistency. Set aside.

Season and Sear the Chicken:

  • While the potatoes cook, mix together all of the chicken seasonings in a small bowl. Season both sides of the chicken evenly.
  • Heat the olive oil in a large skillet over medium-high heat. Once hot, add the chicken, reduce the heat to medium and sear for about 5 minutes per side until nicely golden brown.

Preheat the oven:

  • Preheat the oven to 425°F.

Make the Creamy Veggie Sauce:

  • In the same pan over medium heat, add the butter and diced onions. Sauté for 1–2 minutes until slightly softened. If needed, deglaze the pan with a splash of white wine to lift up all the flavorful browned bits from the chicken. Cook for another 1-2 minutes.
  • Add the leeks and mushrooms and continue to sauté for a few minutes until softened.
  • Add the onion salt, black pepper, paprika, soy sauce, Calabrian chili, chicken bouillon, heavy cream, and water. Stir everything together until well combined. Add the spinach and continue simmering for a few minutes until the spinach wilts and the sauce thickens slightly into a creamy consistency.

Assemble the Casserole:

  • Spread the mashed potatoes evenly into the bottom of a 9” x 11” baking pan. Then place the cooked chicken breasts on top in an even layer.
  • Spoon the creamy leek and mushroom mixture evenly over the chicken. Top everything with the shredded mozzarella cheese and parmesan cheese.
  • Bake for 15–20 minutes, or longer if needed, until the cheese is fully melted, bubbly, and golden brown on top.

Serve:

  • Serve warm and enjoy! This pairs perfectly with a simple side salad or roasted vegetables.
Keyword chicken, comforting, Entree, Main Course, Potato
Tried this recipe?Let us know how it was!