1 (6-ounce) can solid white albacore tuna in water
1 oz baby arugula (2 cups)
Stir together onions, lemon juice, and salt in a small bowl and let stand at room temperature 30 minutes. Add oil in a stream, whisking. Peel grapefruit with a sharp knife. Cut segments free from membranes and transfer segments to paper towels to drain. Halve avocado lengthwise. You’ll only need one half of this avocado, so rub a little lemon juice on the half that still has the seed in it, wrap tightly in plastic wrap and refrigerate. Use within a couple of days. Halve remaining avocado half lengthwise and peel, then cut crosswise into thin slices. Drain tuna and chunk with a fork. Divide avocado and all of tuna between 2 salad plates and arrange grapefruit around them. Top with arugula and drizzle with dressing. Serve immediately. Serves 2.
Arugula is leafy, peppery and pungent. Sometimes you can find it in the produce department of your market wrapped in a bundle with the roots still on it. That’s the best way to buy it. If not, it is often in the plastic packages with the fresh herbs. Always wash well and pat dry. Store in a plastic bag in the refrigerator and use within a couple of days.
Fresh crab meat would be a nice substitute for tuna.
When shopping for avocadoes, find the ones that have a little give when you apply pressure. Firm, unripe avocadoes will ripen on the kitchen counter in a few days. Don’t refrigerate avocadoes until they are ripe.