I have two double boilers. You may know double boilers by another name - Bain Marie - a stove top cooking pot used to cook delicate sauces such as beurre blanc or to melt chocolate (for brownies), which is how I use it. It consists of an upper vessel containing the substance ie chocolate to be melted over the lower pot of water. When brought to a boil, the steam produced in the lower pot transfers heat to the upper pot and gently cooks the sauce or melts the chocolate.
Both double boilers are second-hand. I purchased the one below from Barras Market in Glasgow in the late 1990s while still a studen for £5 from an elderly couple who were selling a variety of used kitchen pots.
Here is the link to the other double boiler that is made from pyrex. I managed to bring it safely from Essex to Glasgow, now it has to be transported from Glasgow to Wales. Will it survive the ride?!
I also have a steamer, that could do a similar job with a bowl suspended over it.
But the steamer comes in handy for a number of things, not just steaming veg of course, but also making steamed puddings. Savoury ones such as Vegetarian Suet Mushroom Puddings and Leek Suet Pudding, also Sweet ones such as Steamed Lemon and Rosemary Pudding.
Do you have a double boiler or are you content with doing it the old way?