On a work surface, sift the flour and a pinch of salt, and arrange in a small pile in the shape of a volcano. Make a hole in the center and pour in the egg and squid ink. Slowly mix with your fingers.
On a floured surface, work the dough until smooth, spread with a roll , fold several times and cut into noodles 5 mm wide. Mix tuna, capers and olive oil in a bowl.
Cook pasta al dente in a pot with boiling salted water, drain and mix with tuna sauce. Serve in a hot container.