Bring a large pot of salted water to a boil. Add halved baby potatoes and cook for about 15 minutes, or until fork-tender. Drain and set aside.

Season cod fillets with salt and pepper. In a large skillet, heat olive oil over medium heat. Add cod and cook for 3-4 minutes on each side until golden brown. Remove and set aside.

In the same skillet, melt butter over medium heat. Add minced garlic, sauté for 30 seconds. Stir in heavy cream and chicken broth; simmer gently. Add rosemary and lemon juice; simmer for 4-5 minutes until slightly thickened.

Fold in the cooked potatoes into the sauce, ensuring they're well-coated. Nestle the cod back into the skillet, spooning sauce over. Warm for an additional 2 minutes.

Transfer to serving plates, drizzle with creamy sauce and garnish with fresh parsley. Serve warm.