First, prepare the sauce by combining the soy sauce, vegan fish sauce, sugar, and thick caramel sauce (or dark soy sauce) in a bowl. Whisk until the sugar has dissolved.
Cut the homemade flat rice noodles into 1-inch-wide ribbons. See notes on how to handle store-bought fresh noodles.
Heat a large wok or nonstick skillet over medium heat and add 1 tablespoon of oil. Add the garlic and sauté until fragrant, about 1 minute.
Add the gai lan, tofu, and toss to combine.
Add the noodles and sauce. Toss the noodles until all of them are coated. (You may use a spatula or chopsticks to help if needed.)
Spread out the noodles and let cook, untouched, to char the noodles a little, 1 to 2 minutes. This step is to give the noodles the wok aroma and flavor.
Taste and season with more soy sauce or vegan fish sauce if needed. Add the ground pepper, then serve with pickled chiles and their vinegar or red pepper flakes.