Preheat your oven to 425°F. Cut potatoes into 1-inch chunks and toss them on a sheet pan with 1.5 tablespoons of olive oil, salt, and pepper. Scatter the smashed garlic cloves and lemon halves around the potatoes. Roast for 20 minutes until the potatoes are just beginning to soften. This head start ensures the potatoes will be perfectly tender by the time the salmon finishes cooking.

While potatoes roast, combine 2.5 tablespoons olive oil, 3 minced garlic cloves, 2.5 tablespoons dried oregano, smoked paprika, red pepper flakes, salt, pepper, and honey in a bowl. This aromatic paste will coat the salmon fillets and infuse them with flavor as they cook. I like to use dried oregano here because it stays crisp and concentrated, while fresh herbs will go into the finishing dressing.

Remove the sheet pan from the oven after 20 minutes. Push the potatoes to one side of the pan. Rub each salmon fillet with the seasoning paste from Step 2, then place them on the empty side of the pan. Top each fillet with 1 tablespoon of butter and arrange lemon slices around the salmon. Return the pan to the oven and roast for 10-20 minutes depending on fillet thickness—the salmon should flake easily with a fork when done.

While salmon cooks, make the finishing dressing. Whisk together 0.4 cup of extra virgin olive oil, fresh chopped parsley, 2.5 tablespoons fresh oregano, torn basil, chopped green olives, champagne vinegar, and fish sauce in a bowl. The fish sauce adds depth and umami without making the dressing taste fishy—trust it and use it! Set the dressing aside.

Once salmon is cooked through, carefully remove the roasted garlic cloves from the sheet pan and chop them into a paste. Stir the garlic paste into the dressing from Step 4 and adjust seasoning with additional salt and red pepper flakes if desired. The roasted garlic becomes sweet and mellow, which balances the bright fresh herbs perfectly.

Divide the roasted potatoes and salmon fillets among serving plates, keeping some of the lemon slices on the plate. Scatter crumbled feta around the salmon, then generously spoon the finished garlic herb dressing over the salmon, potatoes, and feta. Top with fresh arugula for a peppery contrast that cuts through the richness of the butter and feta.