Prepare the tofu: break apart your tofu into irregular bite sized pieces. Gently pat the tofu dry with a paper towel to remove excess moisture.
Prepare Batter: Combine your all purpose flour, water, salt, garlic powder, onion powder, and smoked paprika and whisk into a batter. (It should be a pancake batter consistency). Dip the tofu into the batter and coat evenly.
Preheat and cook tofu: Preheat your air fryer to 400ºF (or heat oil in a skillet if pan-frying). Lightly oil the basket or pan to prevent sticking. Cook approximately 17–20 minutes, flipping halfway through, until all sides are golden and crisp.
Make the sauce: Whisk together dark soy sauce, rice vinegar, white sugar, pineapple juice (¼ cup + 2 tablespoons), and ketchup until smooth. Separately mix cornstarch with 2 tsp water to create a slurry, then stir that into the sauce mixture.
Sauté vegetables: Slice red bell pepper, green bell pepper, and yellow onion. In a skillet with a little oil over medium-high heat, cook onions until translucent, then add bell peppers and cook until they begin to soften but still retain some bite.
Combine & finish: Once tofu and veggies are ready, pour the sauce into the pan, bring to a simmer. Add tofu, gently toss to coat everything in sauce. Continue cooking for a couple of minutes until sauce is thick and shiny, the tofu is heated through, and flavors have melded. Remove from heat; optionally garnish and serve immediately.
Notes
Storage: Keep in an airtight container up to 3–4 days.Reheating: Use skillet or air fryer for best texture.Freezing: Freeze tofu before saucing for best results; thaw, crisp, then add sauce.Substitutions: Tamari for soy sauce (GF), maple syrup for sugar, rice flour or cornstarch instead of flour.