1. Cut the tofu block horizontally into 2 slabs. Place the two pieces side by side on a cutting board covered with plastic wrap. Place another cutting board on top and put 2 to 4 heavy cans on the top board to weight the tofu evenly. Let tofu stand for 45 minutes. Remove the cans and top board and blot the tofu well with paper towels to absorb excess moisture. Cut the tofu into 3/4-inch cubes. If not using immediately, arrange them on a baking sheet covered with paper towels, then cover with plastic wrap. Refrigerate for up to 24 hours. Blot the tofu with paper towels before cooking.
2. In a large nonstick skillet, heat 2 teaspoons sesame oil over medium-high heat. Add half of tofu. Cook for about 10 minutes, turning gently every 2 minutes, until golden. Transfer tofu to a plate. Heat 2 more teaspoons sesame oil in the skillet and repeat the procedure with remaining tofu.
3. Add the remaining 2 teaspoons sesame oil to the skillet. Add the carrots, onion, bell pepper, ginger, and garlic and stir-fry for 2 minutes. Set aside 2 tablespoons of the orange juice mixture in a small bowl and add the remaining orange juice mixture, lime juice, and soy sauce to the skillet. Stir in the tofu, orange zest, basil, and red pepper flakes (if desired). Bring mixture to a boil. Reduce the heat and simmer for about 2 minutes. Add green beans and corn. Cook for about 4 minutes or until beans are crisp but tender. Mix remaining 2 tablespoons of the orange juice mixture with the cornstarch until completely blended and stir into stir-fry. Cook on medium-high heat for 1 to 2 minutes, stirring, until slightly thickened. Season to taste with salt and pepper. To serve, divide the prepared rice noodles among five wide, shallow bowls. Ladle the stir-fry over the noodles.