Melt 15g of butter in a pan and cook the cod fillets for about 4-5 minutes, turning them regularly. Season with salt and pepper. Meanwhile, prepare the mango sauce. Peel the fruit and cut it into large pieces. Place them in a pan with the remaining butter and honey. Cook over low heat until the fruit softens and reaches the consistency of a compote or purée. Add salt and pepper to taste. Serve the cod accompanied by the mango purée.