Begin by placing halved or quartered baby potatoes into a large pot of salted water, bringing it to a boil over high heat. Once boiling, reduce to a medium boil and cook the potatoes for 8–10 minutes until fork-tender. Drain the potatoes and set them aside, allowing them to cool slightly while you move on to the next step.

Pat the cod fillets dry using a paper towel to remove excess moisture. In a small bowl, combine salt, pepper, lemon juice, and zest to create a marinade, then rub this mixture over both sides of the fillets. Let them sit for about 5 minutes.

Preheat a skillet over medium-high heat and add olive oil along with a pat of butter. Once the butter is bubbling and slightly browned (about 1–2 minutes), add the seasoned cod fillets. Sear the cod for 3–4 minutes on each side until golden, then remove and keep warm.

Lower the heat to medium and add a splash more olive oil to the skillet. Add minced garlic and finely chopped shallots, sauté for 2–3 minutes until fragrant and translucent. Stir in fresh rosemary briefly.

Pour in the halal-certified broth and bring to a gentle simmer while scraping the skillet bottom. After 2 minutes, reduce heat to low, add heavy cream and Dijon mustard, allowing the mixture to thicken for about 6–8 minutes.

Return the drained potatoes to the skillet, gently tossing them in the creamy sauce for an additional 3–4 minutes.

Nestle the seared cod fillets back into the skillet, spooning some sauce over the top. Cook on low heat for 2–3 minutes until heated through.

Remove the skillet from heat and garnish with fresh parsley or chives. Serve hot with crusty bread or a crisp salad.