1 cup flour (I’ve been using white whole wheat)
1 egg
~2tbps cool water

1. Mix flour and egg, adding water until flour is just moistened and sticks together
2. Let rest for 5 minutes
3. Knead the dough for 2 minutes. Or you can do it for 10 minutes; more kneading means better developed gluten and a “smoother” noodle.
4. Let rest 10 minutes
5. Roll out or whatever

(adapted from a cooks.com recipe