Weeknight Salmon Au Gratin with Lightened-Up White Wine Sauce and Spinach

Name: Weeknight Salmon Au Gratin with Lightened-Up White Wine Sauce and Spinach
Prep time: 25 min
Cook time: 20 min
Total time: 45 min
Ingredients: 1 1/2 pounds Salmon Fillet (I use Faroe Island; skin removed. (Allow to sit at room temperature for 15 minutes before baking.) ); 2 tablespoons unsalted butter, preferably organic; 1 tablespoon shallots (peeled; minced); 1 1/2 teaspoons garlic (peeled; minced); 2 tablespoons Gluten Free Flour blend (can use regular flour); 1/8 teaspoon freshly cracked black pepper; 2 large pinches cayenne pepper; 2 tablespoons Dry Sherry (can use a dry white wine ); 1 1/4 cups chicken or vegetable broth (low salt! (I use homemade chicken stock)); 1 cup full fat milk; 1 large fresh thyme sprig; 1 1/2 teaspoons fresh lemon juice; 1/4 teaspoon sea salt; 3 cups large leaf fresh spinach; 1/3 cup parmesan reggiano cheese (grated ); 1/3 cup fresh breadcrumbs*; 2 teaspoons extra virgin olive oil; 2 teaspoons fresh parsley (chopped ); 1/4 teaspoon sea salt

By Karen Sheer

5 from 2 votes

Jan 29, 2026

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A quick Creamy Sauce enriched with Sherry tops Salmon Fillets and Spinach Leaves with a crisp Garlic-Herb Sourdough Bread Topping. Lightened-Up, satisfying and Delicious! No cream and gluten free adaptable. I think you will love this Lightenend-Up Salmon Au Gratin dish!

**Weeknight Salmon Au Gratin with Lightened-Up White Wine Sauce and Spinach – Ready to Bake**
**I use Faroe Island Salmon**

Weeknight Salmon Au Gratin with Lightened-Up White Wine Sauce and Spinach - out of the oven — **Weeknight Salmon Au Gratin with Lightened-Up White Wine Sauce and Spinach – out of the oven**

What’s to Love:

THE SAUCE!
I have created a sauce that’s light, and better than a cream based sauce, in my opinion. The method: Heat Butter, add Shallots and Garlic – then Flour (I use a GF blend), pepper and cayenne pepper.
Add Broth (I use chicken; can use vegetable), Dry Sherry, Milk and Parmesan Cheese.

All gets whisked together until slightly reduced.
Fresh Spinach leaves are tossed in… to soften.
All covers Salmon Fillets in a casserole dish and baked for 15 minutes (depends on the size of your fillets.)
The sauce is a lightened up version of three French sauces; Béchamel, Velouté, and Mornay.

Pretty simple preparation for a dish of such sophistication and high quality lusciousness!

THE AU GRATIN TOPPING: Au Gratin: French – “by grating, or “with a crust.”
I use sourdough breadcrumbs – finely chopped with crusts removed or easily blitzed in a small food processor. I do find many Gluten Free people are able to tolerate sourdough. Otherwise, can use gluten free bread.

Method: Add bread crumbs with grated garlic, chopped parsley and a pinch of sea salt. Combine all ad simply top the fish before baking. I do not add Parmesan Cheese to this topping, although you could add a touch… it is in the sauce.

The Ingredients:

1 1/2 pounds Faroe Island Salmon cut into 4 equal pieces.
If serving 2 – a delectable meal the next day!

**Ingredients for the Fresh Breadcrumb Topping (plus sea salt)**

The Method:

**Make and whisk the sauce, reduce 5 minutes**
**Made with Broth, Milk and Sherry – no heavy cream!**
**Serves up especially decadent and creamy**

Fold in the lemon juice, grated Parmesan Cheese, Fresh Spinach and Sea Salt — **Fold in the Lemon Juice, grated Parmesan Cheese, Fresh Spinach and Sea Salt**

Add bread crumbs with grated garlic, chopped parsley and a pinch of sea salt. Combine all ad simply top the fish before baking. I do not add Parmesan Cheese to this topping, although you could add a touch… it is in the sauce.

Add salmon to a casserole dish: space them. Pour sauce over, coating salmon, push spinach to the side. Add Au Gratin breadcrumbs on top of the fish; add lemon slices if you desire.

**Serving the Weeknight Salmon Au Gratin with Lightened-Up White Wine Sauce and Spinach with Noodles to soak up the Sauce**

The Perfect Baking Pan for the Au Gratin:

The vessel best suited for most au gratin dishes is, simply enough, an au gratin pan. It can be round, oval or rectangular, and most commonly it is about an inch and a half deep. The material can be stainless steel, enameled iron, ceramic or glass.
Mine is a vintage enamel coated cast iron one that measures 14″L x 9″W.
The one I own and use often: Dru Holland Au Gratin Pan, Enameled Cast Iron – LeCreuset Style.

Round or oval gratin pans and dishes are ovenproof and shallow, which increases the surface area, thereby insuring a larger crisp portion for each serving.

Weeknight Cooking:

I cook dinner every night, so this is an elegant and easy recipe for me. I’m quite quick in the kitchen! This is a restaurant quality meal that cooks in about 15 minutes. Some prep can be done a day before.

You can make the fresh breadcrumbs mixture the day before and keep covered in the refrigerator. Sauce can be made morning of baking, or a day before and refrigerated.
Make this recipe for company too! Cook in oven before serving.

**Serving the Lightened-Up Salmon Au Gratin**

I like to add cooked Linguine Rice Noodles to the Sauce & Spinach

I hope you love this Au Gratin French Salmon Dish!
Karen

Other Salmon Dishes to Try:

Faroe Island Salmon with Spanish Romesco Sheet Pan Sauce

Outrageous Orange-Chipotle Honey Glazed Salmon

Egyptian Sheet Pan Dukkah Salmon with Veggies & Chickpeas

Salmon in Parchment with Multi-Citrus Salsa

See ALL Fish & Shellfish Recipes

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