Slow-Roasted Salmon with Lemon Dill Mayo
Slow-roasting salmon turns it silky smooth, giving the fat time to melt and leaving you with a luxurious texture. While the salmon is roasting, whip up a super simple Lemon Dill Mayo. And let’s throw some asparagus on the sheet pan while we’re at it – it will cook perfectly at the same time and we’ll be left with a complete meal.
Quick Video
Why You’ll Love This
Flavorful and Tender: Slow-roasting ensures the salmon is perfectly tender and flavorful. The seasonings and the onion mixture meld into the silky salmon and give a big flavor payoff.
Easy to Make: Minimal prep, few dishes, and straightforward steps make this a great go-to recipe. Whether you need to impress guests or just get an easy but satisfying meal on the table for you and your family. It also doesn’t need to be served piping hot so it’s great for occasions when people might be grazing or you can’t get everyone to the table at the same time.
Customizable: Adjust the herbs or spice blend to make it your own. Change the onions for fennel slices. Swap out the asparagus for a different vegetable or leave it out altogether. Change up the sauce with the seasons. The basic method for roasting the salmon remains the same but you can customize the rest to your heart’s content.
Key Ingredients
Salmon Fillet
Opt for high-quality, fresh salmon for the best flavor and texture. The slow-roasting technique makes even thicker cuts turn out juicy and flaky. You can use portioned salmon fillets instead of a whole piece, but you’ll likely need to reduce the cook time just a bit.
Spice Blend (Cumin, Coriander, Fennel)
This trio of spices adds a warm, earthy note that pairs beautifully with salmon.
Red Onion
Combining the sliced red onions with honey, red wine vinegar and olive oil and roasting the mixture on top of the salmon creates a sweet and lightly acidic sauce that infuses extra flavor. You can substitute white or yellow onions or even shallots.
Lemon Dill Mayo
Made with mayonnaise, lemon zest and juice, garlic powder, and fresh dill, this creamy spread balances the rich, roasted flavors with brightness and tang and takes almost no time to prepare.
Step-by-Step Instructions
Step 1: Prepare the Salmon
- Combine ground cumin, coriander, ground fennel seeds, and kosher salt in a small bowl. Rub this spice mixture generously over the salmon fillet and let it sit at room temperature for 20-30 minutes to allow the flavors to penetrate and to take the refrigerator chill off the fish.
- Preheat the oven to 275°F and line a rimmed baking sheet with parchment paper.
Step 2: Prep the Onions
- Thinly slice a small red onion and toss it in a bowl with red wine vinegar, olive oil, a pinch of salt, and a touch of honey.
- Distribute the onion mixture evenly on top of the salmon.
Step 3: Roast the Salmon
- Roast the salmon and onions in the oven for 25-35 minutes or until the salmon is tender and flakes easily with a fork. The onions will soften slightly but not completely.
Step 4: Make the Lemon Herb Mayo
- While the salmon roasts, combine mayonnaise, lemon zest and juice, garlic powder, salt, pepper, and fresh dill in a small bowl. Mix well and set aside.
Step 5: Assemble and Serve
To serve, break the salmon into large rough chunks using a spatula and arrange on a serving platter, spooning the onions over top. Scatter sprigs of fresh dill throughout. Serve as is, alongside the roasted asparagus and lemon dill mayo, or with your grain of choice (rice, quinoa, etc). A really excellent serving option is to serve this with some crusty bread that you can spread with the lemon dill mayo and pieces of the salmon and onions.
Slow-Roasted Salmon with Lemon Dill Mayo
Ingredients
Lemon Dill Mayo
- 1/2 cup mayonnaise or unflavored greek yogurt
- 1 tablespoon fresh dill finely chopped
- Zest and juice of 1/2 a lemon
- 1/2 tsp garlic powder
- salt and pepper to taste
Slow-Roasted Salmon & Asparagus
- 1 teaspoon ground cumin
- 1/2 teaspoon ground coriander
- 1/2 teaspoon ground fennel seeds
- 1 teaspoon kosher salt
- 1 pound salmon fillet (without bones or skin)
- 2 tablespoons olive oil
- 1/2 small red onion thinly sliced
- 1 tablespoon red wine vinegar
- 1 teaspoon honey
- 1 bunch asparagus trimmed
- 1 tsp olive oil
- salt & pepper
Instructions
Lemon Dill Mayo
- In a bowl, mix the mayonnaise, lemon zest and juice, garlic, salt, pepper, and fresh dill. Set aside.
Slow-Roasted Salmon and Asparagus
- Preheat the oven to 275°F.
- In a small bowl, combine the ground cumin, coriander, fennel seeds, and salt. Rub the spice mixture all over the salmon fillet. Let it sit at room temperature for 20-30 minutes to allow flavors to develop and take the refrigerator chill off the fish.
- Thinly slice the red onion and toss in a bowl with red wine vinegar, olive oil, a pinch of salt, and honey.
- Line a rimmed baking sheet with parchment paper. Place the seasoned salmon on the parchment paper and evenly distribute the onion mixture on top of the salmon.
- Toss the asparagus with 1 tsp olive oil, salt and pepper. Arrange next to the salmon on a sheet pan.
- Roast in the preheated oven for 25-35 minutes, or until the salmon flakes easily with a fork and reaches an internal temperature of 125°F. The onions should soften slightly but not completely. Allow to rest for 3-5 minutes
To Serve
- Serve with your grain of choice (rice, quinoa, etc) or with a nice crusty bread and top with dollops of the Lemon Dill Mayo with more on the side to dip the asparagus in. Garnish with more fresh dill.
Frequently Asked Questions
How do I know when the salmon is done?
The salmon is ready when it flakes easily with a fork and reaches an internal temperature of 120-130°F for medium doneness. You may need to adjust the cooking time based on the size and thickness of your salmon fillet or depending on your preference for how well cooked you like your salmon.
Can I prepare the Lemon Dill Mayo in advance?
Sure! The Lemon Dill Mayo can be made up to two days ahead and stored in an airtight container in the refrigerator.
Love This Recipe? Rate and Comment!
If you enjoyed this Slow-Roasted Salmon recipe, please consider leaving a rating and a comment below! Your feedback helps others and keeps me inspired to create more delicious recipes for you to enjoy.
