Alheira is the dish to look for in Mirandela. The sausage is smoky, garlicky, and softer than chouriço, traditionally made with bread and mixed meats rather than leaning only on pork. In town it usually arrives fried, with a crisp skin, an egg, and potatoes.
You don't need a famous restaurant to understand the appeal. Pick a simple local dining room, order it as the main event, and treat the meal as part of seeing Mirandela rather than a break from it.