Place the vinegar, water, sugar, and salt in a small saucepan and heat over medium-high heat, stirring frequently. Remove the pan from the heat as soon as the sugar and salt have dissolved.

Wash or peel the carrots and either slice them thinly using a mandoline or cut them into very thin sticks with a knife. Wash the chili pepper, peel and halve the shallot, and cut both into thin rings.

Place the vegetables in a clean screw-top jar and pour in the vinegar solution. Seal the jar and set aside for 20 to 30 minutes.

Meanwhile, gently press the tofu dry between some kitchen roll or a clean dish towel using the palms of your hands, then cut it into slices 0.5 to 1 centimeter thick.

Place the tofu slices and cornstarch in a large (approximately 2.5-liter) freezer bag and seal it. Carefully turn the freezer bag over so that the cornstarch mixes with the tofu without crumbling the tofu slices. Continue turning the freezer bag back and forth until the cornstarch has completely coated the tofu and no longer sticks to the bag.

Heat oil in a large, non-stick frying pan. Add the tofu slices and fry over medium-high heat for 3 to 5 minutes, or until the underside is golden brown. Season the tofu generously with salt, then turn and fry for another 3 to 4 minutes on the other side, until it too is golden brown and nicely crispy.

Cut open the banh mi baguettes or baguette rolls. Spread mayonnaise and sriracha evenly over the rolls. Distribute the coriander (including the stems) and tofu slices over the baguettes as well. Finally, top with the pickled carrots, shallots, and chili peppers, fold the banh mi closed, and serve immediately.