There should be more recipes that use bananas. Whenever you use a banana (either in a recipe or by eating it), you drop a banana skin and leave it lying on the ground. You can't pick these up (they're too yucky and slimy to want to do that), but they will eventually decompose and disappear.
When someone walks over a banana skin, there's a small (say 1 in 5) chance that they will slip on the banana skin and fall over, and as they do so, an object (at random) falls out of one of their bags. The player then gets up and dusts themselves off (perhaps sporting a small bruise for a little while afterwards), but they must remember to look for the thing they dropped and pick it up again - otherwise they'll lose it...