If you’re using a stove like the MSR Wisperlight or one of the XGK family, and you’re using it for more than heating water and melting snow, more expedition cooking, one thing you cannot live without is a simmer plate. These come in many styles, and have many names, including ‘burner plate’ and ‘simmer ring’. This is not a piece of high tech kit or expensive: just a ring plate of steel or alloy, sometimes flat, sometimes with raised sections, sometimes with holes. How it’s used is it’s just put over the flame, allowing the heat to be dissipated over a wider area, making the heat more even on the pan. This makes it much easier to simmer food, or cook food more slowly and is ideal for things like porridge or rice when using only a 1/1 ratio of water to rice, or baking. It’s also invaluable when using a pressure cooker.
The best one to get is a light stainless steel one, which works better than the alloy kind, and with a light folding handle, making it easy to lift it on and off the stove. Make sure you don’t buy a huge one, as it only needs to cover the bottom of your pans, and if you don’t want to buy one, then a paint can lid also work.