Clean the mushrooms and cut into slices. Drizzle with 2-3 tablespoons of oil, season with salt and pepper. Cut the chorizo very small.
Beat the eggs until frothy, mix in the mushrooms and chorizo.
Heat the oil in a pan and pour the egg mixture into it. Depending on the size of the pan, the mixture is enough for 1-2 tortillas. Let it set slowly over a low heat. When the tortilla is firm, place a plate over it and turn the pan so the tortilla slides onto the plate.
Cut the tortilla into 2 x 2 cm cubes. For tapas, skewer 2 pieces each on a wooden stick and serve.