Well, don't bin all your leftovers.
Please consider giving them to your garden birds. The days are very short for them at this time of year and they would appreciate lots of the things we don't always eat; like Christmas cake.
I usually have a bowl full of leftovers which I collect in the fridge and then zap in the food processor once a week and put a portion into the bird house each morning. It's free entertainment for me, it helps them to survive and is much better than chucking it into landfill.
Our leftovers include things like pasta, rice, potatoes, cheese, cake, pastry and even scrambled egg.
Oh, and before someone mentions that we should be feeding them 'proper' bird food (which you have to pay for), things like sunflower seed, suet, mealworms, etc then yes, I already do that!
I really enjoy watching the birds and hope to inspire one or two of you to take up this as a new hobby in 2024.