Carefully remove tofu from package. Silken tofu can be quite fragile. If using the kind that comes in a plastic carton, I recommend running a butter knife or a spatula around the edge to help the tofu release cleanly. It can also be helpful to slice off a small piece from the corner of the carton — this can help release the vacuum so the tofu comes out more easily.

If you plan to serve the tofu cold, you can flip the block of tofu onto a clean, lint-free kitchen towel to blot off some of the extra moisture. You can let it sit and drain on the towel while you prepare the sauce. Then transfer it to a plate or bowl when ready to serve.

In a small skillet, combine white parts of scallions, garlic, brown sugar, soy sauce, rice vinegar, toasted sesame seeds, and chili crisp. Heat over medium-high, stirring often, until the mixture begins to bubble.

Let the sauce simmer for about 1-2 minutes, until sugar has dissolved. The sauce will thicken slightly. Stir in the green parts of the scallions (reserving a few to use as a garnish) and cook for about 1 more minute. Remove from heat and stir in the optional toasted sesame oil.

The dish can be served with the tofu cold or hot. I prefer to heat mine by poaching it. Poaching will make the dish a little more brothy because the tofu will retain some of the poaching liquid. I like this — the extra broth is good with rice. (If you prefer the dish to be less brothy, you can try microwaving the block of tofu or even steaming it on a heat-safe plate very carefully.)

To poach, carefully lower the block of tofu into a pot with enough water to cover it by about an inch. Bring this to a gentle simmer over medium-high heat. Then reduce the heat to low or medium-low to keep the simmer nice and gentle. (If it boils too vigorously it can start to make your tofu fall apart.)

It usually takes about 5-8 minutes to heat through. Carefully use a slotted spoon or skimmer to lift the tofu out of the water. Let the excess water drip off before transferring it to a bowl to serve.

To serve, the tofu can be left as a whole block or sliced. (I also sometimes enjoy cutting a crosshatch pattern into the top of the tofu.) Cutting it is more for presentation than anything else.

Whether serving hot or cold, pour the prepared sauce over the tofu. Top with reserved scallion greens and serve.