Kikkoman Executive Chef Andrew Hunter makes a delicious twist on onion rings using portabella mushrooms. He cuts the portabella mushroom caps using ring cutters of various sizes, then roasts, breads, and fries them. The crispy and meaty mushroom rings are finished with a drizzle of sweet and savory Kikkoman Sushi Sauce, or unagi tare. These mushroom rings make a fabulous savory and crispy appetizer, or a delicious addition to a burger or salad. The mushroom rings are crispy on the outside and have a great meaty texture on the inside.