Save This creamy Chicken Dijon and Mashed Potato Casserole is pure comfort on a chilly night. Imagine tangy Dijon-coated chicken tucked under a golden, cheesy topping of fluffy mashed potatoes. It comes together easily and transforms ordinary ingredients into a family-style main that tastes like you cooked all afternoon.
I first made this casserole for a Sunday dinner when I needed something that felt homey but a little special. Now it is my go-to when I want to impress with minimal effort the leftovers are always gone by the next day
Ingredients
- Russet potatoes: the classic choice for fluffy mashers pick ones with firm skins and no green patches
- Unsalted butter: gives the potatoes richness always use fresh for the best flavor
- Whole milk: makes the mash smooth and creamy shop for milk with rich taste and freshness
- Sour cream: ups the tang and silkiness use full fat for best texture
- Olive oil: helps brown the chicken and brings a fresh undertone choose extra virgin if possible
- Boneless skinless chicken breasts: stay tender in the sauce look for plump even pieces
- Yellow onion: brings aromatic sweetness chop finely for even cooking
- Fresh garlic: adds punch and subtle heat always use fresh cloves over jarred
- Low sodium chicken broth: deepens the flavor pick a broth with strong aroma and clear golden color
- Dijon mustard: gives the signature tang use a classic French brand for authenticity
- Heavy cream: creamy richness smoothes out the sauce be sure it is not ultra-pasteurized for best results
- Fresh tarragon: an herby lift entirely optional but delightful fresh is superior
- Gruyère or Swiss cheese: nutty melt and classic French flavor freshly grated melts best
- Fresh parsley: bright color and herbaceous finish make sure it is vibrant green
Instructions
- Prep the Oven:
- Set oven to four hundred degrees Fahrenheit or two hundred degrees Celsius so there is no waiting later
- Cook the Potatoes:
- Put cubed potatoes in a large pot and cover completely with cool salted water potatoes cook evenly this way Bring water just to a boil then gently simmer until potatoes are totally fork-tender about fifteen minutes do not rush this step for creamy results Drain and return potatoes to the pot keep warm to help the mash stay fluffy
- Mash the Potatoes:
- Add butter to warm potatoes and mash until most lumps are gone Pour in half the milk add sour cream generous pinch of salt and black pepper Mash and stir until mixture is smooth and creamy add a bit more milk as needed until the texture is just right taste for seasoning
- Sauté the Chicken:
- Heat olive oil in a big skillet over medium-high until shimmering Scatter chicken pieces into an even layer salt and pepper generously Cook without stirring until the first side is golden then toss and keep cooking until nearly done about five to six minutes Remove the chicken so it does not get dry during the next step
- Build the Sauce:
- With chicken out set heat to medium and add the chopped onion cook slowly until very soft and sweet about three to four minutes Stir in garlic for one more minute until fragrant Pour in chicken broth use a spoon to scrape all the tasty brown bits from skillet bottom Add Dijon mustard and heavy cream whisking well so the sauce is even and smooth Simmer just until the sauce thickens lightly about three minutes Add tarragon if desired and return chicken get all pieces coated
- Assemble Everything:
- Lightly grease a nine by thirteen inch baking dish Pour chicken and sauce right into the dish spreading to the corners Spoon mashed potatoes in large dollops over the chicken then smooth them with a spatula for a gentle thick topping
- Add Cheese Topping:
- Sprinkle Gruyère or Swiss cheese evenly over the mashed potatoes so every bite melts richly
- Bake Until Golden:
- Put casserole on the center rack and bake uncovered twenty to twenty-five minutes look for deep bubbly edges and golden spots on top
- Rest and Garnish:
- Let the dish cool for five minutes so everything sets Sprinkle with parsley for color as a final touch then serve in big scoops
Save I look forward to the nutty aroma of Gruyère bubbling atop the potatoes every time I bake this My kids always fight over those cheesy corner pieces and it honestly tastes even better for lunch the next day
Storing Your Casserole
Keep leftovers in a tightly covered dish in the fridge for up to three days Warm up individual servings in a low oven with a sprinkle of extra milk to keep the mash fluffy This casserole also freezes well cool it fully wrap airtight and freeze for up to two months let thaw fully in the fridge before reheating
Swapping Ingredients
Use rotisserie chicken to save time Swap Yukon Gold potatoes for an even creamier mash Try sharp cheddar or mozzarella if Gruyère is out of reach
Serving Suggestions
A big green salad with bright vinaigrette keeps things balanced Roasted green beans or steamed peas add color Crusty bread helps scoop up the saucy bits
Save This casserole transforms leftovers into something special and brings a warm French twist to any weeknight dinner.
Recipe FAQs
- → What type of potatoes work best?
Russet potatoes yield creamy, fluffy mashed potatoes ideal for layering and baking in casseroles.
- → Can I use chicken thighs instead of breasts?
Yes, boneless chicken thighs add extra richness and remain tender after baking.
- → Which cheese substitutes well for Gruyère?
Cheddar or mozzarella can be used; cheddar offers sharpness, while mozzarella brings mild creaminess.
- → How do I prevent a runny casserole?
Ensure the sauce simmers to thicken and let mashed potatoes cool slightly before assembling.
- → Is fresh tarragon necessary?
Tarragon is optional; it adds a delicate herbal note, but the casserole is flavorful without it.
- → What sides pair well?
A crisp green salad and a glass of Chardonnay complement the creamy, savory profile of this dish.