Preheat the oven to 400°F and line a small baking sheet with parchment. Set aside.
Once you've dried off the tofu, cut it into 3/4 inch cubes and place the cubes on the parchment lined sheet. Drizzle tofu with the 2 teaspoons of olive oil and top with the chili flakes, lime zest, salt, pepper and lime juice. Toss to combine and slide the tray into the oven. Roast tofu until brown edges appear and there's a detectable crispy-ness, about 25 minutes. Flip and toss the tofu cubes about halfway through.
Meanwhile, cook the soba noodles according to package directions. Once cooked, drain noodles and set aside.
Heat the 3 cups of vegetable broth in a small saucepan over medium heat. Add a fat pinch of salt to the broth and bring to a boil. Keep at a medium simmer until ready to serve.
Very finely mince or microplane the garlic cloves into two separate soup bowls. Top the garlic with the chopped white parts of scallion, and ground black pepper to taste
Divide the soba noodles, sliced kale and roasted tofu among the soup bowls. Pour the hot broth over top. Garnish the soup with remaining chopped scallions and more salt and pepper if you like. Serve with lime wedges.