In a large bowl, combine the flours and 2 teaspoons salt. Make a well in the center. Whisk the eggs, 1/2 cup water and oil; pour into well. Stir together, forming a dough. Cover and let rest for 10 minutes.
Turn dough onto a floured surface; knead 8-10 times. Divide into fourths. Roll each portion into a 14x12-in. rectangle. Cut widthwise into 1/2-in. strips; cut strips into 6-in. lengths. Let noodles rest on a clean towel for at least 1 hour.
In a Dutch oven, bring remaining water to a rapid boil. Add noodles; cook for 8-10 minutes or until tender. Drain.
In the same pan, cook the butter over medium heat for 3-4 minutes or until golden brown. Add the noodles, pepper and remaining salt; toss to coat.