Steps
1. Press tofu to remove excess moisture, then cut into cubes.
2. Heat vegetable oil in a pan over medium heat.
3. Add shallots and garlic, sauté until fragrant and golden.
4. Add sliced chicken breast and stir-fry until cooked through.
5. Add tofu cubes and stir gently to avoid breaking.
6. Toss in carrots, cucumber, and tomatoes; stir-fry for 2-3 minutes.
7. Add soy sauce, oyster sauce, sugar, salt, and pepper; mix well.
8. Cook for another 2 minutes until vegetables are tender but crisp.
9. Remove from heat and garnish with fresh chili slices if desired.
10. Serve hot with steamed rice or noodles.