From Food Blogga; although the recipe calls for tofu, a firm white fish or shrimp can be used in place of the tofu. Other greens can also be used, including mizuna or bok choy.
Serves 2

2 Tablespoons soy sauce
1/4 teaspoon rice vinegar
2 teaspoons brown sugar
2 teaspoons lime juice
2 teaspoons minced fresh ginger
1/4 teaspoon cayenne pepper
6 ounces extra firm tofu, cut into "steaks"
1 Tablespoon sesame oil, divided
2 small bunches of tat soi
1-2 teaspoons toasted sesame seeds

In a small bowl whisk all ingredients from soy sauce through cayenne pepper.

In a large skillet over medium high heat, add 2 teaspoons sesame oil. Add tofu steaks; cook for 5-7 minutes per side, or until golden brown. Remove from skillet. Add remaining 1 teaspoon sesame oil to skillet; add tat soi; once wilted, add sauce. Reduce heat to medium-low, and cook just until sauce slightly thickens.

Divide greens on plates. Top with half of the tofu. Drizzle with remaining sauce, and sprinkle with sesame seeds. Serve immediately.