First, press the tofu to remove excess water. Pat the block dry with paper towels, then wrap it in a clean towel. Place something heavy, like a cast iron skillet, on top for about 15 minutes. Once pressed, cut the tofu into 1/2-inch cubes.
While the tofu is pressing, prepare your sauce. In a small bowl, whisk together the low-sodium soy sauce, water, rice vinegar, maple syrup, sesame oil, minced garlic, minced ginger, red pepper flakes, kosher salt, and black pepper. Set it aside for later.
Heat one tablespoon of vegetable oil in a large non-stick skillet or wok over high heat. Add the tofu cubes and cook until they are lightly golden brown on each side, which should take about 1-2 minutes per side. Pour in 1/4 cup of the prepared sauce and stir to coat the tofu as it bubbles. Remove the tofu from the skillet and set it aside on a plate.
Wipe out the skillet and add the remaining tablespoon of oil. Sauté the white parts of the scallions for a minute until they soften. Add the diced peppers and cook for two minutes. Next, add the broccoli florets and continue cooking for another two minutes before adding the snow peas. Sauté for 1-2 minutes more until all vegetables are crisp-tender.
Pour the rest of the sauce into the skillet with the vegetables. Let it simmer for a minute, allowing the flavors to meld. Stir in the cooked brown rice and the reserved tofu. Continue cooking until the rice is warmed through and has absorbed most of the sauce. Finally, fold in the sliced green scallions just before serving.