I LOVE this idea! I'm always wanting more culture-type panels, and this is right up that alley. I would, of course, say that this panel would be even better if you could do a physical making of the bentos (with it perhaps being a paid, ticketed event for materials), but I'm not sure on the logistics of having food at the hotel... I'm pretty sure it's not allowed, which is terribly unfortunate
Food aside, I've always loved the idea of bentos, and I've made a couple myself (very amateur..). I'm fascinated by the super pretty/creative ones, and I'm very intrigued by your allergy/food-sensitivities alternatives (I'm paleo and allergic to dairy and egg, so I'm somewhat limited, myself.. cali-rice sounds like a great idea! might have done it myself, but never thought of it like that
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I'd go
Can't really offer you much guidance on your mother, though.. That's a bit above my pay grade