Peppery watercress balances the sweetness of the grapefruit and the richness of the avocado and salmon in this light, bright dinner salad.
If you buy bunched watercress, be sure to wash it thoroughly. You'll also need to trim the tough stems. It's fine to leave some thinner stems near the leaves intact.
Starting the salmon on a preheated baking sheet creates an initial blast of heat that firms up the exterior. The fish then gently cooks through in a low oven.
The doneness notes below are for farmed salmon; if you're using leaner wild-caught salmon, cook it until the center of the fillet registers 120 F for best results.
SALMON, AVOCADO, GRAPEFRUIT AND WATERCRESS SALAD
Start to finish: 45 minutes
2 (8-ounce) skin-on salmon fillets
3 tablespoons plus 1 teaspoon extra-virgin olive oil
Salt and pepper
1 small shallot
1 teaspoon white wine vinegar
1 teaspoon Dijon mustard
1/4 cup skinned hazelnuts
4 ounces (4 cups) watercress
Adjust oven rack to lowest position, place aluminum foil-lined rimmed baking sheet on rack, and heat oven to 500 F. Pat salmon dry with paper towels, rub with 1 teaspoon oil, and season with salt and pepper.
Once oven reaches 500 F, reduce oven temperature to 275 F. Remove sheet from oven and carefully place salmon, skin side down, on hot sheet. Roast until center is still translucent when checked with tip of paring knife and registers 125 F (for medium-rare), 9 to 13 minutes. Let salmon cool on sheet to room temperature, about 20 minutes.
While salmon cools, cut away peel and pith from grapefruits. Holding fruit over bowl, use paring knife to slice between membranes to release segments. Measure out 2 tablespoons grapefruit juice and transfer to separate bowl.
Mince shallot. Whisk vinegar, mustard, shallot, and 1/2 teaspoon salt into grapefruit juice. Whisking constantly, slowly drizzle in remaining 3 tablespoons oil until incorporated.
Toast hazelnuts in 10-inch skillet over medium heat, shaking pan occasionally, until golden and fragrant, 3 to 5 minutes; transfer to small bowl to cool, then chop cooled nuts. Tear watercress into bite-size pieces. Halve avocado, remove pit, and cut into 1/4-inch-thick slices. Coarsely chop 1/4 cup mint.
Arrange watercress in even layer on platter. Using two forks, flake salmon into large 2-inch pieces. Arrange salmon pieces, grapefruit segments, and avocado on top of watercress. Drizzle dressing over top, then sprinkle with mint and hazelnuts. Serve.
Nutrition information per serving: 436 calories; 249 calories from fat; 28 g fat (4 g saturated; 0 g trans fats); 62 mg cholesterol; 389 mg sodium; 23 g carbohydrate; 7 g fiber; 12 g sugar; 27 g protein.