Toast Cashews: In a large non-stick pan, over medium heat, toast cashews for 4-6 min, stirring occasionally, until golden-brown. Transfer to a plate and set aside.
Prepare Sauce: Meanwhile, make the sauce. In a small bowl, whisk together all sauce ingredients until combined. Set aside.
Prep Tofu: Slice the block of tofu in half, lengthwise and then into three long strips. Use your hands to break each strip into 1-inch sized pieces, or cut into cubes. Breaking the tofu by hand results in a crispier exterior. Transfer tofu to a medium bowl. Sprinkle cornstarch over top and season with salt and pepper. Toss to coat.
Fry Tofu: In the same pan, heat 2 tsp cooking oil of choice over medium-high heat. When the oil is hot, add the tofu. Cook for 5-7 min, flipping pieces occasionally, until tofu is golden-brown and crisp on all sides. Depending on the size of your pan, you may have to do this in batches. You don’t want to overcrowd the pan.. Transfer to a plate and set aside.
Stir Fry Vegetables: To the pan, add another 2 tsp oil. Add the carrots, onions, peppers and broccoli. Cook for 5-7 min, stirring often, until tender-crisp.
Finish Stir Fry: Add tofu, cashews and sauce to the pan with the veggies. Cook for 1-2 min, stirring constantly, until sauce is thickened and slightly reduced.
Serve: Serve cashew tofu over white rice, brown rice, quinoa or noodles. Sprinkle green onions over top and chili flakes, if desired.