What are "Entresijos" and "Gallinejas"?

We've recently had in Madrid the festivities in honor of its patron saint "San Isidro" (which official day is May 15th). They're celebrated in the "pradera de San Isidro" (medow), where you can find many food stalls and fairground rides. Two of the most traditional foods in Madrid are "Entresijos" and "Gallinejas", and they can be found almost in every stall there these days.
But what are they? Find it below!

Shikku Izakaya

In a tweet: Some people say it's the third best Japanese restaurant in Madrid. Very elegant; expensive. Can be good for business meetings or celebrations. It has a bar downstairs to have cocktails. They have more restaurants in Madrid.

Summary

Concept	Comment
Overall Score	7.9.
Price per Person	50 €. With one bottle of Albariño (white wine from Rias Baixas, Galicia: "Mar de Frades", 22€) and no desserts. We had 2 cocktails later in the bar, for another 10€each.
Food Type	Japanese