Chop the parsley, chives and shallots. Tear your celery leaves from the stalks. Set aside.
Place a medium sized mixing bowl in the large bowl of ice. Preparing this on ice keeps it nice and cool all the way through. Skin the salmon filet. Clean any brown flesh left behind you want the salmon to be bright pink. Chop the filet into small 1/4-inch cubes. Put the salmon in a mixing bowl. Add the parsley, chives, shallots and celery leaves.
Grate in a heaping tablespoon horseradish. Add the arugula. (If you can't find micro arugula, regular arugula can work just tear the leaves into smaller pieces.) Add a pinch sea salt, and zest in half a lemon. Toss in the croutons. Drizzle with olive oil. Salmon is a fatty fish, so don't be too generous. Add 2 splashes jalapeno sauce, and a pinch ground pepper. Toss together. Serve on a cold plate, and garnish with a pinch grated horseradish.
Keep the salmon on ice that way it's sure to stay really fresh.