Preheat the oven to 400 degrees Line a large rimmed baking sheet with parchment paper and lay the salmon fillet on it. Pat dry with a paper towel.
Whisk the oil, lime zest, and garlic together. Grate the jalapeño and smell for spiciness. If it is very spicy (or you are sensitive to spice) add only half the grated pepper. Otherwise, add it all to the oil mixture. Pour the mixture over the salmon fillet and salt the pepper liberally.
Bake for 10-14 minutes, until just cooked through, but not dry. Squeeze lime juice over the top and serve warm.