• 1 pound fingerling or new potatoes
• 2 teaspoons stone-ground mustard
• 3 tablespoons fresh lemon juice, divided, plus 4 wedges
• 2 teaspoons olive oil, divided
• Salt and pepper, to taste
• 1 (1-pound) fennel bulb, halved, cored, and thinly sliced with stalks reserved
• 1/4 of a small red onion, sliced (about 1/8 cup)
• 4 (5-ounce) halibut fillets
• 2 tablespoons low-fat sour cream
• 2 teaspoons prepared horseradish
• 1 garlic clove, minced
• 1/2 cup panko (Japanese breadcrumbs)
1. Cover the potatoes with 2 inches water in a small saucepan; bring to a boil. Simmer 15 minutes or until fork-tender. Drain, halve, and transfer to a bowl. Immediately toss potatoes with mustard, 1 tablespoon lemon juice, 1 teaspoon olive oil, and salt and pepper, to taste.
2. Preheat oven to 400°.
3. Toss fennel in a bowl with remaining 2 tablespoons juice, remaining 1 teaspoon oil, onion, and 2 tablespoons fennel fronds.
4. Rinse fish, and pat dry. Arrange in a single layer, skin side down, on a small shallow baking pan. Combine sour cream, horseradish, and garlic in a bowl. Spread evenly on top of fish, and top with panko. Roast fish 7 minutes or until tops are golden brown and fish is just cooked through.
5. Divide potatoes among 4 serving plates with fennel salad, fish, and lemon wedges. Garnish with fennel fronds; serve.