Baked Zucchini with Miso Tomato and Onion

Trim off ends of zucchini. Cut into about 1-inch tall cylinders. Using a knife, scoop out the center of the cylinders without piercing through the bottom. Mix miso paste, tomato and onion. Fill each zucchini cylinder with miso filling. Place in a baking dish. Bake for 10 to 15 minutes.