Preheat your oven to 400°F (200°C).

Arrange the sliced potatoes on a baking sheet.

Lightly drizzle with olive oil, then sprinkle with salt and pepper, tossing everything to ensure a thorough coating.

Arrange the mixture in a single layer to promote uniform cooking.

Roast for 20-25 minutes, flipping halfway through, until the potatoes are golden and tender. Set aside once done.

Season both sides of the cod fillets with salt and pepper.

Heat 1 tablespoon of olive oil in a large skillet over medium heat.

Add the cod fillets and sear for 2-3 minutes on each side until lightly golden.

Transfer the cod to a plate and set aside.

In a large skillet, warm one tablespoon of olive oil over medium heat until it’s hot and ready for sautéing.

Introduce the diced onion to the skillet and sauté until it becomes tender, which should take around 3 to 4 minutes. Then, mix in the minced garlic and continue cooking for an additional minute until fragrant.

Pour in the chicken or vegetable broth, scraping the pan to lift any browned bits.

Allow it to simmer for 2 minutes.

Add the heavy cream and rosemary, stirring well. Simmer the sauce for 5-6 minutes, allowing it to thicken slightly. Season with lemon juice, salt, and pepper to taste.

Return the cod fillets to the skillet, spooning the rosemary cream sauce over each piece.

Allow the fish to cook in the sauce for another 5 minutes, or until fully cooked and flaky.

To serve, arrange the roasted potatoes on each plate and place a cod fillet on top.

Drizzle with extra rosemary cream sauce and garnish with fresh rosemary sprigs if desired.