For meal prep, shape the burger patties up to 2 days in advance and keep them covered in the refrigerator until ready to cook. Cooked patties and leftover creamy tomato feta sauce can be stored in airtight containers in the refrigerator for 3 to 4 days and gently reheated in a covered skillet over low heat. To keep the burgers juicy, avoid pressing down on them as they cook and let them rest before serving so the juices redistribute. Customize the heat level by adding more or less red pepper flakes and adjust the sauce thickness with a splash of extra cream or a few more feta crumbles to reach your preferred consistency.