Kettle for my Trangia
It isn't properly used until the plastic on the handle has melted, and the molten plastic has thumb inprints, reminding the owner of the incident. They work finely on plain fires as well, and while I suspect you'll be using them for a typical "brew" (i.e tea) the only proper
modus operandi is boiling coffee.
This is done thusly:
1. Obtain coarsely ground coffee. French press ground is quite OK. In Sweden, you'd buy "Kokmalet".
2. Fill kettle with cold water. Preferably from a stream, well, or if necessary, a tap.
3. Pour coffee grounds on top of water. They'll float first, but that'll cease.
4. How much? More than naïvely thought, but no precise amount can be given. You'll learn through a process that people who talk about "frameworks" and "Software devlopment" call "continuous delivery", a method normal people call "trial and error" combined with "iteration through all possible variables until things happen to not break" .
5. Put on heating source. When coffee/water mix boils, remove from heat, allow to settle and pour carefully.
6. Drink, while observing rate of coffee grounds passing lips.
7. On rate threshold trigger, remove cup, allow a second settlement, and try again.
8. Do not remove boilt grounds from pot; instead re-use together with more water and some grounds. After some 3 boils, you're getting somewhere.
Hot beverage trivia: When the Swedish army bought Centurion tanks in the 50's, they of course came with a kettle. This was very well received by the tankers, who from then on insist that a tank is not worthy of their consideration unless it's got a kettle. Thus, one of the mods that turn the Leo 2 into a Strv 122 is "install kettle".