For Meatless Friday, Barb Szyszkiewicz topped a mustard-marinated salmon fillet with plenty of caramelized onions. Download our printable recipe card!
Because caramelized onion-smothered entrees are comfort food for me, I decided to try adding those onions to salmon with a savory mustard sauce. I take the term “smothered” very seriously, so it’s up to you to decide how many onions you want to use with this dish. While the onions take a little time, the rest of it is very simple to make.

Dijon Salmon Smothered in Onions
Makes 4 servings
Ingredients:
1 1/2 lb. salmon fillet
baking spray or olive oil for the pan
2 TBL Dijon mustard (I used whole grain, but it will work with whatever kind of Dijon mustard you have on hand)
2 TBL brown sugar
2 cloves garlic, minced
2 TBL olive oil
salt and black pepper to taste
2 large sweet onions
1 TBL olive oil
Directions:
Prepare your baking pan by brushing it with olive oil or spraying with baking spray. Place salmon on the pan.
Mix mustard, brown sugar, garlic, 2 TBL olive oil, and salt and pepper to make a paste. Spread over salmon.
Allow the salmon to marinate about 30 minutes. As the salmon marinates, slice the onions, then caramelize them in a large skillet with 1 TBL olive oil. When they’re done, remove from heat, cover, and rest until salmon is cooked.
Preheat the oven to 425. Bake the salmon 15-20 minutes or until done.
Top salmon with caramelized onions before serving.

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Copyright 2026 Barb Szyszkiewicz
Images: copyright 2026 Barb Szyszkiewicz, all rights reserved.
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