Halibut in Hazelnut Romesco with Potatoes

INGREDIENTS

• 2 garlic cloves, chopped
• 1/2 cup low-salt chicken broth
• 1/2 teaspoon salt
• Chopped fresh parsley (optional)
• 12 baby Yukon Gold potatoes, halved, steamed until tender
• 4 tablespoons extra-virgin olive oil, divided
• 1/2 cup husked hazelnuts (about 2 1/2 ounces)
• 1 tablespoon unsalted butter
• 1/4 teaspoon cayenne pepper
• 1 teaspoon Sherry wine vinegar or red wine vinegar
• 1 1/2 teaspoons smoked paprika*
• 1/2 cup coarsely chopped drained piquillo peppers from jar or can
• 4 6-ounce halibut fillets
• 1 large tomato (about 9 ounces)