Cut tofu crossways into 1/4cm-thick slices. Place tofu between paper towels until barely moist. Cut slices crossways into 1/4cm cubes.
Heat oil in a large nonstick frying-pan over medium-high heat. Add tofu; sauté for five minutes, browning on all sides. Add chillies, garlic, ginger, spring onion, celery, sliced cabbage; cook for three minutes, stirring frequently. Add the sauce and cook for one minute. Remove from heat.