You can, but you won't get the lovely browning on the cheese. For crock pot stuffed peppers, put in the crockpot in a single layer. Cook on low for 6 to 8 hours, or on high for 3 to 4. The time will depend on how big the peppers are. Sprinkle with cheese and put the lid back on until the cheese is melted, 5 to 10 minutes.