Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Is the bottom of the skillet ridged or flat? I have a glass-top stove and prefer a flat bottom.
Document: I have not experienced any rusting however, if that's a fear you can always fill the bottom a pan with water the place on stove top to boil...once done and cooled you should be able to get the food off.
I love this skillet! It makes perfect grill marks - as if you had truly grilled. Also, I love to cook steaks and fish on the stove top and then put this straight into the oven to finish it off. This pan makes it easy! And it is very easy to clean. The only minus is that it is heavy. But worth it!
Best pan I own....Cook on top of the stove or put it under the broiler.....Easy to clean...Gave this to my son also...Love it!!! !
I love my little grill, vegetables, steaks are perfect for the stove top. I recommend the handle cover, it gets hot.
I actually have this skillet and the smaller square grill pan as well. I use this one more for light grilling a sandwich, whereas I've used the smaller one more to actually cook meat on. As another reviewer states, it takes quite a long time to cook something like a chicken breast or a steak. It does turn out good but as also stated, it caused a lot of smoke as well. Thats because the bottom of the grill gets all the juices and they burn while the meat slowly cooks.
What can I say? I'm a bona fide Le Creuset fan so adding another piece to my cerise collection just makes me happy. This is a gorgeous skillet so am looking forward to all my steak dinners and anything else I decide to experiment with. Am now deciding what to buy next - decisions, decisions :-)
I would highly recommend that you purchase this skillet. I spent a fair amount of time reading reviews/comments on all the various skillets available. I was hesitating on spending this much money, but I am happy I took a chance on this.I think it is wonderful to cook with, and I am very satisfied with it.
I recently purchased this cast iron skillet for the amazing sale price of under $60 (thank you Amazon!). It had been on my wish list for well over a year, and I was thrilled to see it listed at such a great price. I have been very happy with it's performance thus far.This is my fourth piece of Le Creuset cast iron cookware.
(1) Where is it written, who decreed that skillets should be round? (2) Why has it taken me so long to discover the advantages of a square fry pan?The answers are: nowhere that I know of, and because my mother always used a round skillet. She would have loved this enameled cast iron beauty that leaves appetizing sear marks on meat - a char effect without the mess.
I also don't go over medium setting. The other annoying thing with this is how difficult it is to clean. Plan to spend time with a brush. It is not non-stick at all. I would rather use my old cast iron skillet to cook meat on, and use these for more regular cooking or light grilling. So for the price, I can't really recommend this skillet. I do love Le Creuset's porcelain enameled cookware however. That is the best.
Answer: The bottom is flat and enamelled so it will not scratch your cooktop.