This method can even be used in a RV to save your propane. Why use 20 minutes of fuel (and extra cost) when you can use 7 minutes of fuel and get the same result?
I love to cook at my campsites but sometimes it's easier to just eat bars, nuts and other foods that don't require cooking and cleanup. Some of the issues that also impact my tendencies to cook at a campsite are:
Bring your water to a boil and add your food. Turn down the flame to a medium level and stir until everything is mixed and under the water level.
Shut down the stove, cover the pot and put it on a safe surface.
Cover the pot with a cozy, (described below) clothing or whatever you have. Do NOT use fabrics that melt like nylon or acrylics.
Let the food slow cook in it's own heat and hot water.
Your pans are easier to clean in the end because they don't have burnt food on the bottoms.
Make your own
There are may be a couple places that make and sell these a pot cozy but you always have a fit issue for your own pots.
If you do much camping, it's worthwhile to make a custom cozy for your pots. Ideally, this would be a cozy that wraps the pot except for the top. Then make another cover piece for the lid. Use material that doesn't melt. Wool works great. Cotton is okay. Materials like those used for ironing boards, hot pads, welding blankets or hot gloves. You could also use reflective insulation that is sold in rolls at most hardware stores.
Remember , although duct tape is great for a million things, it has plastic in it and will melt. Instead of duct tape, use an aluminum tape. This is also easily found at hardware stores.
This is a great technique for pots, skillets, coffee pots, drink mugs, anything you want to keep warm longer and more efficiently.