If you are meal prepping this eggplant lasagna for later, you can make the most of this recipe ahead of time. You can prepare the layers by roasting the eggplant, making the cheese layer, and cooking the mushroom sauce. Store in the fridge separately up to 6 days before, and assemble and bake the day of. You can also store the entire thing in the fridge assembled up to 4 days before and bake when ready.