1 teaspoon grated lemon zest
2 tablespoons fresh lemon juice
1 clove garlic, minced
1/2 teaspoon sugar
3/4 teaspoon kosher or sea salt
Freshly ground pepper
3 cups thinly sliced fennel bulb (fronds reserved)
2 bunches arugula (about 1/2 pound total), stemmed
1. Make vinaigrette: In a small jar with a tight-fitting lid, combine 1/4 cup extra-virgin olive oil, lemon zest and juice, garlic, sugar, salt and lots of pepper. Several good grinds of pepper make the vinaigrette taste robust, a perfect complement to the fennel. Cover tightly and shake vigorously to blend. Taste and adjust the seasoning. Set aside.
2. Chop the fennel fronds and measure out 1/3 cup. In a large bowl, combine the fennel, 1/4 cup of the fennel fronds (saving the rest for garnish) and the arugula. Toss lightly to mix and set aside.
3. Season the salmon on all sides with a little salt and pepper. Place a large, heavy skillet over medium-high heat.
4. When the skillet is hot, add the 3 tablespoons of olive oil and swirl to coat the pan. Add the salmon and cook about 4 minutes. Carefully turn the salmon and cook until the fillets are almost opaque throughout, but still very moist, or an instant-read thermometer inserted in the center registers 125 to 130 F, about 4 minutes. Transfer to a warm plate and set aside while you toss the salad.
5. Shake the dressing vigorously again and toss with the salad.
6. Arrange the salad on 4 dinner plates. Place a salmon fillet in the center, garnish with the remaining fennel fronds and serve immediately.