3. Tossing with a fork or your fingers, drizzle in the ice water. Stop adding water when the dough starts to come together, and grab it in your hands. If it holds together easily, without crumbling, it’s ready. If it has dry spots, or pieces break off easily, add a bit more water until it’s totally cohesive. Add in your egg yolk, and vinegar, toss to combine with a fork. You may still see streaks of egg yolk. That’s perfectly fine!