Bonju Solution

Set the "Mad About Orange" avatar as your active avatar.

Then mix the above three items (Orange Juice, Gourmet Cooking For Your Pet, Blumaroo Steak) at the Mystery Island Cooking Pot. (Take note: Mystery Island, not Bonju's!)

It is unknown if this avatar is seasonal or not. The latest Editorial mentions that: there's only a few more days left to figure out the combination before the secret of the Bonju avatar is going to remain a mystery for another year -- however, they might just be referring to its discovery.