Preheat your oven to 400°F (200°C).

Halve the baby Yukon Gold potatoes and place them in a bowl. Drizzle them with olive oil, then season generously with salt and pepper. Toss until evenly coated, then spread them out on your baking sheet in a single layer. Roast in the preheated oven for 25-30 minutes.

While the potatoes are roasting, pat your cod fillets dry with paper towels. Season both sides generously with salt and pepper.

In a large skillet, melt 1 tablespoon of butter and heat a splash of olive oil over medium-high heat. Once hot, add the seasoned cod fillets. Sear for 3-4 minutes on each side until golden brown and flaky.

Reduce the heat to medium and return to the skillet. Add the remaining tablespoon of butter; once melted, add minced garlic and sauté for about 30 seconds. Then, add chopped rosemary and sauté another 30 seconds.

Pour in the heavy cream, stirring to combine. Allow the mixture to simmer gently for 3-4 minutes until it thickens slightly. Adjust seasoning with salt and pepper.

Carefully return the seared cod to the skillet, nestling it within the sauce. Add the roasted potatoes, ensuring they are coated in the sauce. Allow everything to simmer together for about 2 minutes.

Transfer the Cod and Potatoes with Rosemary Cream Sauce to serving plates. Sprinkle fresh parsley over the top and serve hot.