Seared Tuna & Watercress with Scallion-Ginger Relish

Make Ahead Tip: Prepare through Step 2, cover and refrigerate for up to 6 hours.

Tips for Two: Store leftover water chestnuts in the refrigerator, covered with water; they keep for up to 1 month with daily water changes. Add to a stir-fry; toss in a green salad; jazz up chicken or tuna salad; Asian Brown Rice.

Tip: To toast sesame seeds, heat a small dry skillet over low heat. Add sesame seeds and stir constantly until golden and fragrant, about 2 minutes. Transfer to a small bowl and let cool.

People with celiac disease or gluten-sensitivity should use soy sauces that are labeled "gluten-free," as soy sauce may contain wheat or other gluten-containing sweeteners and flavors.