These tuna wraps were inspired by spicy tuna sushi rolls. We love how they taste with peppery watercress, but other greens—such as arugula, romaine, escarole or even radish sprouts—would taste great in the filling. If you want to play on the sushi inspiration, add pickled ginger and stir some wasabi into the soy sauce for dipping. Serve with sliced cucumbers and slivered red onions tossed with rice vinegar, a little oil and a pinch of salt.