Cut each slice of brioche into 2 triangles. Beat the eggs and milk in a shallow bowl with a fork.
Heat half the butter in a largefrying pan. Quickly dip the bread, a triangle at a time, into the egg mixture, then put as many as you can get into the frying pan. Cook over a medium heat until the underside is golden. Turn over and cook the second side, then remove from the pan and keep warm. Heat the remaining butter in the pan and dip and cook the remaining brioche triangles.
Transfer the cooked triangles to 4 serving plates, top with spoonfuls of yogurt, a scattering of berries and a light dusting of sifted icing sugar or a drizzle of maple syrup. Serve immediately.