Step 1

In a small bowl, whisk together the shallot, garlic, chile, if using, lemongrass, soy sauce, oyster sauce, maple syrup and vinegar until smooth.

Step 2

Cut the tofu lengthwise into six 1/2-inch-thick slabs. Take three of the slabs, stack them and cut them in half lengthwise again, and repeat with the other three slabs, to yield 12 batons. Carefully transfer them to a 9-by-13-inch baking dish in one layer. (Medium-firm tofu can be a little delicate.) Pour the marinade over the tofu in the dish and let stand for at least 15 minutes (or cover and refrigerate up to 8 hours).

Step 3

In a large skillet over medium heat, heat the oil until it shimmers. Working in batches if needed to avoid overcrowding, carefully add the batons, leaving as much of their marinade behind in the baking dish as possible. Fry the tofu until golden on each side, about 5 minutes per side. Transfer to a serving platter.

Step 4

Add the rest of the marinade and the coconut water to the skillet, letting it sizzle and reduce until syrupy, 2 to 3 minutes.

Step 5

Spoon the sauce over the tofu on the platter, sprinkle with the cilantro and sesame seeds and serve warm.