The cool flavors in this relish would be great with tuna or shrimp.
Ingredients
2 teaspoons yellow mustard seeds
3/4 teaspoon fennel seeds
1/4 cup white wine vinegar
2 tablespoons olive oil
1 tablespoon sugar
2 1/4 cups 1/4-inch pieces unpeeled seeded English hothouse cucumber
1 cup chopped red onion
1/2 cup coarsely chopped watercress
Directions
Stir mustard and fennel seeds in small skillet over medium-high heat until mustard seeds begin to pop, about 2 minutes. Transfer to medium glass bowl. Whisk in vinegar, oil and sugar. Add cucumber and onion; toss to combine. Season with salt and pepper. Let stand at room temperature 30 minutes, stirring occasionally. (Can be made 4 hours ahead. Cover; chill.) Mix watercress into relish and serve.
