4-5 (4 oz.) pieces salmon, about ¾-inch thick*
Coarse salt and freshly ground pepper
For the aioli:*
1 large egg yolk
4 tsp. freshly squeezed lemon juice
¼ cup olive oil
6 tbsp. canola or vegetable oil
¼ tsp. kosher salt
1 clove garlic, minced or pressed
2-3 tbsp. minced fresh chives
Freshly ground pepper, to taste
Focaccia sandwich rolls
Romaine or bibb lettuce leaves
Thinly sliced red onion
Thinly sliced cucumber
Thinly sliced tomato
Preheat the oven to 425˚ F. Line a rimmed baking sheet with foil. Place the salmon pieces skin side down on the foil. Brush the tops lightly with olive oil and season with salt and pepper. Roast for 15-16 minutes, or until the internal temperature just registers 160˚ F on an instant-read thermometer. Remove from the oven and let cool slightly.
Meanwhile, make the aioli. In a small bowl, combine the egg yolk with the lemon juice and whisk lightly. Begin to drizzle in the olive and canola oils in a steady stream, whisking constantly and quickly to create an emulsion. Continue whisking until the mixture is significantly thickened and spreadable. Blend in the salt, garlic and chives. Season with pepper to taste and adjust other seasonings as necessary.
To assemble, spread a thin layer of the aioli on the inside of the focaccia. Layer with the lettuce leaves. Use a spatula to separate the salmon from the skin on the foil, and place the salmon on the sandwiches. Top with layers of red onion, tomato and cucumber. Sandwich together and serve
A note about the salmon:
The thickness of salmon fillets can vary quite a bit. An optimal thickness for this is about ¾-inch. If you have a piece that is super thick (1½ or so inches), split it in half horizontally so that you end up with two pieces of the desired thickness.
A few notes about the aioli:
This calls for a raw egg yolk. If you are not comfortable with this or have a medical concern related to consuming raw egg, buy pasteurized eggs.
Though I used chives, any number of herbs could be great here. Dill is a natural pairing with salmon and would be excellent. Experiment with what you have available.
I have seen methods for making aioli using food processors, blenders, and immersion blenders. I just used a whisk and elbow grease but those methods may work just as well.