1. Mix the flour and salt, and add the egg, butter, and milk. Then, knead the dough for five minutes till it reaches a smooth texture. Then, cover it and leave it to sit for 10 minutes.
2. Dust a surface on the countertop with flour and roll out the kneaded dough to ¼ or 1/8 inch thickness. Then, cut it into preferred shapes and lengths. Leave the egg noodles to air-dry.
3. Put salt to water in a saucepan and let it roll to a boil. Then, cook the noodles until the texture is al dente. Drain the water and serve the egg noodles as preferred.

Also, this video can help you know more.