If you hate the aggressive taste of a raw onion like myself then this is a must try. I refuse to eat onions any other way I always have them on hand and use them for just about everything I cook well except pie..
all the ingredients are subject for change, I will use all the onions in a bag I buy, but you can use however many you want to. I do not suggest only using 1. The amount of oil and butter is up to you and how many onions you use. try and use as little as you can of the butter or oil but you do not want the pan to be dry.
Peal off the skins I actually at times will peel off the first layer of the onion as this layer will almost always get tough such a waste but I find they cook better. Cut both ends off and lay the onion flat. Cut it in half turn on its side and slice it down the middle (carefully) turn it on its side flat side on the cutting board. Slice it with one of the ends facing you. Do not slice it to thin because of the long cooking time the onion tends to get tough
Toss all the onions in the pan with the melted butter or oil. You can put as many as the pan will hold just leave enough room so you can turn them over and over you will have to do this many times over the next few hours. I set my electric stove on 2 or 3. I then sprinkle in my salt and pepper again us as much or as little as you like if you cant eat salt don't use it if you forget to use it just toss it in at the end.
The slower and longer you cook it the better results you will get no matter how aggressive your onion is in the end it will be as sweet as candy. I will put mine on in the morning and just go about my day and turn them every 20 min or so. 6 large onions will reduce to a cup or so of deep dark sweet onions. Ready for any dish or the freezer.
Some times when onions are on sale I will buy a ton of them I will slice them up as stated put them in one of those freezer bags you can suck the air out of and save them for use later. if you don't have one of those machines try and double bag them or here is a trick you might not know of, stick a straw in the bag about two inches close the bag up to the straw. Now suck the air out when all the air is out remove the straw with your teeth keep sucking the air out as you are removing the straw and with your free hands close the bag at the same time. sounds very silly but works really well.
When you go to brown frozen onions you will find there will be a ton of water don't worry, I will set my stove top on 5 or 6 and let most of the water cook off then go back to my 2 or 3 to brown or if your lazy or way to busy to stand there while the water cooks off just leave it on 2 or 3 it will just take a bit longer. At some point during the cooking process you might find a bunch of brow gooey stuff on the bottom of the pan just toss in 1/2 cup of water or if you love wine go for it and scrap it up with the onions that is the best part..yum