Place the instant udon noodles in a large heat proof bowl. Pour hot water into the noodles to separate these. Leave the noodles to soak for 3-4 minutes or until chewy to your liking. You can also cover the bowl to keep the steam in. Afterwards, drain the water from the bowl. You can leave some liquid just to help mix everything together better. (See below if using frozen udon)
If using frozen udon, place a 'brick' of udon in a microwave-safe bowl and cover it with a microwave-safe lid. I microwave the udon noodles for around 2.5 to 3 minutes or until chewy to my liking.
Add in the soy sauces, vinegar, syrup or other sweeter, sesame oil, sesame seeds, scallions, tofu, and chili garlic sauce/chili crisp oil.
Mix together until the noodles are well coated. The noodles will also absorb some of the sauces as it sits in the mixture.
Taste the noodles and feel free to season with more soy sauce, chili garlic sauce, etc, if you’d like, to taste. Enjoy!