Mix salt with flour and then pour in water. The dough can be slightly hardened at the first. Knead forcefully until almost smooth. Wrap with plastic wrapper and rest for 15 minutes. Then continue kneading for 2 or 3 minutes, wrap well, rest for another 15 minutes. If you have enough time, more-kneading during the process makes the noodle more chewier and whiter. You can knead it for 2-4 times during the 1 hour resting.
When the resting is done, continue kneading for half of minute, and then roll the dough out into a large rectangle (around 4mm to 6mm in thickness). Then cut the rectangle into wide strips (around 6 to 8mm in wide too). Slightly stretch the noodles.
Bring a large pot of water to a boiling and then add salt. Place the noodles in, cook for around 3 minutes (for thicker version: 5 minutes )until the noodles are just cooked. Don't over cook the noodles!
Transfer the noodles to serving bowl, add sweetened soy sauce, sugar, garlic, chili oil, sesame paste and then top with Sichuan peppercorn powder. Mix well and serve hot!