Begin by freezing the salmon for about 15 minutes; this will make it easier to slice. Once chilled, pat the salmon dry to remove excess moisture, then carefully cut it into ¼-inch planks. Next, slice the planks into strips and finally dice them into small cubes. Arrange the salmon neatly in a bowl.

In the bowl with the diced salmon, add 1 tablespoon of olive oil, finely diced red onion, chopped capers, Dijon mustard, lemon zest, and lemon juice. For a touch of heat, incorporate the finely diced jalapeño. Gently toss all the ingredients together until the salmon is well coated.

Allow the salmon mixture to rest for about 5 to 10 minutes at room temperature.

Using a round mold, if you have one, gently pack the tartare mixture for a polished presentation, or simply serve it straight from the bowl.