How do I clean a burned omelette from my cast iron frying pan?

Hot water and Dawn dish soap. let the skillet soak at least 8 hours fully covered in water and Dawn. You will have to do some scrubbing, I used steel wool pads and it came out like new. The hard part is you will have to "Cure" your skillet again. For instructions on how to cure your skillet, look on the internet. If you do not "Cure" your skillet again, everything will stick to it.

Thanks will try that

Salt

Add 2 cups water with 1 Tablespoon of dish detergent. Boil for three minutes. Let sit until cool, Use a steel wool pad to "GENTLY' scrub out omelet. Rinse well. Put back on stove after drying pan . Heat cast iron pan until hot-5 minutes. Cool and wipe or spray with oil.