You can have this tasty Fish and Mashed Potatoes dinner ready in just 30 minutes. It's perfect for your busy weeknights. This recipe shows you how to sauté white fish fillets with a simple lemon-butter sauce. It also shows you how to make creamy mashed potatoes. Together, they make a delicious meal!
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How to Time This Meal Perfectly
This dish has several components: fish, mashed potatoes, and a light lemon butter sauce to pour over the fish.
To time this meal perfectly, cook the potatoes first because they take longer than the fish. While the potatoes cook, prepare the fish. When the mashed potatoes are ready to serve, cook the fish so it's hot when you serve it.
- Prep: Before you begin, gather your ingredients and cooking utensils.
- Cook the Potatoes: Start by cooking the potatoes. As you peel and cut them, add them to the pot of water as it heats to prevent discoloration.
- Make the Sauce: Combine butter, minced garlic, lemon juice, and chopped parsley in a saucepan over low heat.
- Prepare the Fish: While the potatoes cook, rinse, dry, and season the fish with salt and pepper. Dredge in flour.
- Cook the fish in a heavy skillet with butter and olive oil.
- Mash: Drain and mash the potatoes while the fish cooks.
- Serve hot: Once the fish and mashed potatoes are cooked, serve immediately while hot. Garnish with chopped parsley.
What You Need
- Thin white fish fillets such as snapper, mahi mahi, tripletail, hogfish, trout, etc.
- Russet or Yukon Gold potatoes
- Unsalted butter
- Olive oil
- Milk or heavy cream
- Lemons
- Fresh herbs such as parsley, basil, or thyme
- Salt and black pepper
See recipe card below for exact amounts.
How To Make Creamy Garlic Mashed Potatoes
After boiling the potatoes, drain them in a colander and return them to the warm pot for a few minutes. This helps dry out the potatoes, so they're creamier.
- Place the potatoes in a large pot and cover with cold water by 1 inch. Add a generous pinch of salt, bring to a boil, then reduce the heat and simmer until very tender, about 15 minutes.
- Drain the potatoes and return them to the pot. Mash with 2 tablespoons butter, then gradually mix in the warm milk or cream until smooth and creamy. Season with salt and pepper.
Mashed Potato Add-Ins
Moisten the potatoes with heavy cream, or use milk, sour cream, crème fraiche, Greek yogurt, or lots of butter.
For additional flavor, add green onions, chives, roasted garlic, caramelized onions, grated cheese, horseradish, Dijon mustard, or crispy bacon.
How To Sauté Fish
Sautéing fish is an easy way to cook it on the stovetop.
- While the potatoes cook, melt 2 tablespoons butter with 2 minced garlic cloves in a small saucepan over low heat. Stir in the juice of half a lemon and the parsley. Cover and keep warm.
- Pat the fish dry and season with salt and pepper. Coat both sides lightly with flour and shake off the excess.
- Heat 1 tablespoon olive oil and ½ tablespoon butter in a large skillet over medium heat. Add 1 smashed garlic clove and two fish fillets. Cook for 2-3 minutes per side, until opaque and easily flaked with a fork. Repeat with the remaining oil, butter, garlic, and fish.
- Divide the mashed potatoes and fish among four plates. Spoon the lemon-garlic butter sauce over each serving and serve with lemon wedges.
Should I Flour Fish Before Cooking?
Flouring fish before cooking can make it slightly crispy and help the seasonings adhere. However, if you prefer a lighter coating, you can skip the flour.
I coated two fillets with salt, pepper, and all-purpose flour. I seasoned the other two with just salt and pepper.
As you can see in the photos, the floured fish developed a beautiful golden color, while the fish without flour remained mostly white after cooking.
The flour-coated fish held together better during cooking. The coating helped the fillets maintain their shape, making them easier to transfer from the pan to the plate.
For a gluten-free meal, replace the all-purpose flour with brown or white rice flour. Keep in mind that rice flour may not brown as deeply, so the fish may look similar to fillets seasoned only with salt and pepper.
Storage and Leftovers
Store leftover fish and mashed potatoes in an airtight container in the refrigerator for up to two days. You can layer the fish over the potatoes for easy storage.
Reheat them gently in a skillet, adding a splash of milk or cream to the potatoes if they need extra moisture.
Garnish For This Fish Dinner
Serve the fish over the mashed potatoes and spoon the lemon-butter sauce on top. Garnish with chopped parsley and fresh lemon wedges.
Add a colorful side dish, such as green peas. My kids love the combination of fish, mashed potatoes, and peas!
For more presentation ideas, see my guide to Garnishing with Parsley.
Final Thoughts
This Fish and Mashed Potatoes with Lemon Butter Sauce is comfort food at its best-the perfect dinner for a relaxed Sunday evening.
Season the fish simply with salt and pepper, or add a little Old Bay or blackened seasoning for extra flavor. A light coating of flour gives the fish a golden finish and helps the fillets hold together when served.
For smooth, creamy potatoes, use a handheld masher or potato ricer. Gradually add butter and cream, then season generously with salt and pepper.
Serve with steamed peas or one of my favorite vegetable recipes for an easy dinner everyone will enjoy.
FAQ
Absolutely! Creamy mashed potatoes are a great side dish. They go well with all types of fish, whether it's fried, baked, grilled, or pan-seared.
For extra creaminess, add sour cream, Greek yogurt, cream cheese, or additional butter. For more flavor, try Parmesan, cheddar, Gruyère, roasted garlic, caramelized onions, chives, or parsley.
Yes. Prepare the mashed potatoes in advance and store them in an airtight container in the refrigerator. Reheat them gently on the stovetop or in the microwave, adding a little butter, milk, or cream if needed.
For extra creaminess, add sour cream, Greek yogurt, cream cheese, or additional butter. For more flavor, try Parmesan, cheddar, Gruyère, roasted garlic, caramelized onions, chives, or parsley.
Try mashed cauliflower, parsnips, or sweet potatoes. Cauliflower is a lighter, lower-carbohydrate option, while parsnips and sweet potatoes add a naturally sweet flavor.
Fish and Mashed Potatoes
Equipment
- Large pot
- Colander
- Potato masher
- Small saucepan
- Large skillet
- Shallow dish
Ingredients
- 2 pounds Russet or Yukon Gold potatoes, peeled and diced
- 5 tablespoons unsalted butter, divided
- ¼ cup heated milk or cream
- 4 6-ounce thin white fish fillets (snapper, hogfish, trout, mahi, etc.)
- 1 tablespoon olive oil
- 4 garlic cloves
- 1 lemon
- ¼ cup all-purpose flour (use rice flour for gluten-free)
- 3 tablespoons chopped parsley or another herb (chives, basil, thyme, etc.)
- salt and pepper
Instructions
For the mashed potatoes
- Place the potatoes in a large pot and cover with cold water by 1 inch. Add a generous pinch of salt, bring to a boil, then reduce the heat and simmer until very tender, about 15 minutes.
- Drain the potatoes and return them to the pot. Mash with 2 tablespoons butter, then gradually mix in the warm cream until smooth and creamy. Season with salt and pepper.
- Place the potatoes in a large pot and cover with cold water by 1 inch. Add a generous pinch of salt, bring to a boil, then reduce the heat and simmer until very tender, about 15 minutes.
Cook the fish
- While the potatoes cook, melt 2 tablespoons butter with 2 minced garlic cloves in a small saucepan over low heat. Stir in the juice of half a lemon and the parsley. Cover and keep warm.
- Pat the fish dry and season with salt and pepper. Coat both sides lightly with flour and shake off the excess.
- Heat 1 tablespoon olive oil and ½ tablespoon butter in a large skillet over medium heat. Add 1 smashed garlic clove and two fish fillets. Cook for 2-3 minutes per side, until opaque and easily flaked with a fork. Repeat with the remaining oil, butter, garlic, and fish.
- Divide the mashed potatoes and fish among four plates. Spoon the lemon-garlic butter sauce over each serving and serve with lemon wedges.
Notes
- For extra creaminess: Use milk, heavy cream, half-and-half, sour cream, cream cheese, crème fraîche, Greek yogurt, or additional butter.
- For extra flavor: Mix in sliced green onions, chives, roasted garlic, caramelized onions, grated cheese, horseradish, Dijon mustard, or crumbled bacon.
- Gluten-Free Option: Replace the all-purpose flour with white or brown rice flour, or omit the flour entirely. Check all packaged ingredients to ensure they are certified gluten-free.
