Cod and Potatoes Recipe

Name: Cod and Potatoes Recipe
Ingredients: 1 pound of Yukon gold potatoes cut into 1-inch pieces; 1 pound of cod fillet cut into 4 pieces; 2 teaspoons of kosher salt; ¼ teaspoon of freshly ground black pepper; 3 cloves of garlic (minced); 1 large onion (chopped); 2 sprigs of fresh rosemary; 2 teaspoons of Dijon mustard; ¼ teaspoon of ground cayenne pepper; 2 tablespoons of drained capers; 2 tablespoons of lemon juice from 1 lemon; 2 tablespoons of salted butter; 1 cup of heavy cream; ½ cup of chicken or fish broth; 3 tablespoons of extra virgin olive oil; 2 tablespoons of chopped flat-leaf parsley optional; 1 teaspoon of lemon zest