Soak dry rice noodles in boiling water for the amount of time recommended for stir-fries (read instructions on the package. It varies depends on the brand).
Rinse under cold water then leave the noodles in a bowl of cold water. Cut them into shorter strips with scissors.
Mix the sauce
Mix all the ingredients for seasoning. Set aside.
Heat up oil in a wok (or a deep frying pan) over high heat until it smokes. Pour in the beaten egg. Break it into small pieces with a spatula.
As soon as the egg is cooked, add onion & garlic. fry for 30 seconds or so.
Take rice noodles out of the water and put directly into the wok.
Add the seasoning prepared earlier. Stir fry constantly until the noodles are evenly heated.
Stir in baby spinach and fresh chilli. Turn off the heat immediately once the spinach wilts.
I don’t recommend that you cook for more than two servings at once unless your wok or frying pan is very big and your heat source is powerful enough for a large volume of ingredients. Cook in batches if you need more servings.