Dedicate your fifth day to experiencing the gastronomic delights of Gran Vía. Start your day with a delicious breakfast at one of the charming cafes in the area. Then, embark on a food tour to sample the diverse flavors of Spanish cuisine. Try traditional tapas, paella, churros, and other mouthwatering dishes. Don't forget to visit the Mercado de San Miguel, a vibrant food market where you can taste a variety of local delicacies. End your day with a glass of Spanish wine at a cozy wine bar.