Heat oil in a skillet over medium-high heat. Add tofu, carrots, celery, onion, and garlic; cook and stir until vegetables are just soft; 5 to 10 minutes. Season with salt and pepper.
Stir rice, egg, and spinach into tofu mixture until egg is no longer runny, about 5 minutes. Stir in Sriracha sauce; season with salt and pepper.