Salmon Spaghetti with Lemon Garlic Sauce

Bright, simple, and wildly satisfying, this Salmon Spaghetti with Lemon Garlic Sauce is the kind of dinner that looks special but comes together in under 30 minutes. Tender chunks of salmon mingle with toasted walnuts, briny baby capers, peppery watercress, and a glossy lemon-garlic sauce that coats each strand of spaghetti. It’s perfect for weeknights, easy entertaining, or the night you want pasta that feels elevated without fuss.

Why you’ll love this Salmon Spaghetti with Lemon Garlic Sauce

• Speed: From stove to table fast—pasta cooks while the sauce comes together.
• Flavor balance: Zesty lemon and garlic, crunchy walnuts, and salty capers play against buttery salmon.
• Texture: Soft salmon, al dente spaghetti, crisped sourdough croutons, and crunchy watercress make every bite interesting.
• One-pan friendly: The sauce and protein cook in the same skillet, keeping cleanup minimal.

Ingredients

• 2 lemons, squeeze out lemon juice and zest
• 1 clove garlic, minced
• 2 ounces toasted walnuts
• 1/3 cup grated parmesan cheese
• 13 ounces spaghetti
• 1/3 cup olive oil
• 2 tablespoons baby capers
• 2 slices sourdough bread, cut into bite-sized cubes
• 1 pound skinless salmon fillets, cut into 1-inch thick bite-sized pieces, season with salt and ground black pepper
• 2 3/4 tablespoons unsalted butter
• 2 ounces watercress leaves

Prep tips before you start

• Bring a large pot of salted water to a boil for the spaghetti; it will save precious minutes if it’s ready as you begin the sauce.
• Cut the salmon into uniform 1-inch pieces so they cook evenly. Pat them dry and season with salt and ground black pepper just before cooking.
• Zest and juice the lemons first so they’re ready to go into the sauce at a moment’s notice.
• Toast the walnuts in a dry skillet until fragrant if they aren’t already toasted—watch closely; they brown fast.
• Cube the sourdough into consistent bite-sized pieces so they crisp evenly when sautéed.

Step-by-step instructions

Below is a clear, ordered set of steps to make this Salmon Spaghetti with Lemon Garlic Sauce. Follow them in sequence for the best results.

1. Bring a large pot of water to a rolling boil and add a generous pinch of salt. Cook the 13 ounces spaghetti until al dente according to package directions. Reserve 1 cup of the pasta cooking water, then drain the spaghetti and set it aside.
2. While the pasta cooks, heat a medium skillet over medium heat and add the 1/3 cup olive oil. Once the oil shimmers, add the 2 slices sourdough bread cut into bite-sized cubes. Fry, stirring occasionally, until the bread cubes are golden and crisp on all sides—about 4 to 6 minutes. Remove the toasted croutons with a slotted spoon and set them on a paper towel-lined plate to drain.
3. In the same skillet, reduce the heat slightly and add the 2 3/4 tablespoons unsalted butter. When the butter melts, add the 1 clove garlic, minced, and sauté for about 30 seconds until fragrant but not browned.
4. Add the seasoned 1 pound skinless salmon fillets cut into 1-inch pieces to the skillet. Cook the salmon in the butter-garlic mixture for 3 to 4 minutes, stirring gently so the pieces brown on the outside but remain tender inside. Turn or stir carefully to avoid breaking the salmon into flakes too early.
5. Once the salmon pieces are lightly seared, add the juice and zest from the 2 lemons to the pan. Stir to combine and allow the bright lemon flavor to come through. If the skillet looks dry, pour in about 2 ounces of the reserved pasta water to create a silky sauce and help deglaze any browned bits from the bottom.
6. Stir in the 2 tablespoons baby capers and the 2 ounces toasted walnuts. Let the capers warm through and the walnuts become coated in the lemon-garlic butter for about 1 minute.
7. Add the drained spaghetti to the skillet and toss gently with the salmon, lemon-garlic butter, capers, and walnuts. If the pasta needs more moisture, add more reserved pasta water, a tablespoon at a time, until the sauce clings to the noodles and has a smooth sheen. The total amount of reserved water used will vary, so add just enough to reach a glossy, saucy consistency.
8. Remove the skillet from heat and stir in the 1/3 cup grated parmesan cheese until it melts into the pasta, creating a creamy finish. Taste and adjust seasoning with additional salt and ground black pepper if needed.
9. Toss in the 2 ounces watercress leaves just before serving so they wilt slightly but retain a peppery bite.
10. Plate the Salmon Spaghetti with Lemon Garlic Sauce, then sprinkle the toasted sourdough croutons over the top for crunch. Finish with an extra grind of black pepper, an optional lemon zest sprinkle, and a few reserved whole walnuts for presentation if desired. Serve immediately.

Serving suggestions

This Salmon Spaghetti with Lemon Garlic Sauce works beautifully with a simple green salad dressed in a light vinaigrette or a side of oven-roasted asparagus. For a heartier meal, add steamed green beans or a bowl of marinated olives and pickled vegetables. A crisp white wine like Sauvignon Blanc or a light, citrus-forward rosé pairs very nicely.

Make-ahead and storage

• Make-ahead: Cook the spaghetti and prepare the lemon-garlic sauce and salmon separately. Reheat gently in a skillet and toss with freshly cooked pasta right before serving.
• Storage: Refrigerate leftovers in an airtight container for up to 2 days. Reheat over low heat with a splash of water or olive oil to revive the sauce. Add fresh watercress just before serving to maintain its texture.
• Do not freeze the finished dish; the texture of the salmon and watercress will degrade when thawed.

Variations and swaps

• If you prefer a nuttier crunch, swap the walnuts for toasted almonds or pistachios in the same 2-ounce amount.
• For a dairy-free version, omit the 1/3 cup grated parmesan cheese and increase the lemon zest by 1/2 teaspoon for brightness. You can also use a dairy-free grated alternative in the same quantity if you like.
• If you don’t have watercress, baby arugula or spinach (use the same 2 ounces) can stand in; add them at the end so they wilt slightly.
• For extra heat, add a pinch of crushed red pepper flakes while sautéing the garlic.

Notes on ingredients and technique

Using skinless salmon makes each bite easier to eat and keeps the sauce smooth. If your salmon has skin, you can remove it before cutting into 1-inch pieces. Toasted walnuts add a toasty counterpoint that complements lemon and capers. If you taste the sauce and it feels too sharp from the lemon, a splash of the reserved pasta water and the parmesan will round it out.

When tossing the pasta with the sauce, work quickly but gently so the salmon stays in nice chunks and the spaghetti gets evenly coated. The reserved pasta water acts as a natural emulsifier, helping olive oil, butter, lemon juice, and cheese bind to the noodles.

Final thoughts

This Salmon Spaghetti with Lemon Garlic Sauce is a bright, cozy dish that celebrates clean flavors and varied textures. It’s an easy way to make seafood feel like a treat without complicated steps or long ingredient lists. Whether you’re feeding a crowd or cooking for yourself, this panful of lemony pasta is approachable, flavorful, and deeply satisfying.

Enjoy—cheers to simple weeknight elegance.