This is a container of hot water in which sauces and dishes can be kept hot in small pans, until required.
Alternatively, it is a method of gently cooking items in a water bath in the oven. A large pan of water is kept near boiling. A second heat-resistant pan holding the item to be cooked is placed into the water (in contrast to double boiling, where it is kept above the water.)

Deglazing pans:
This is a way to lift the tasty browned bits left in a pan. Add a few Tbsp60 - 75 ml of liquid and bring to the boil, stirring and scraping up the bits from the pan, then pour the condensed liquid over the recipe.

Double boiling:
Also called Double saucepan or double fond melts chocolate (or anything that needs to be cooked gently - like pudding) without scorching it. You need a pan and a second heat-resistant container (a glass or steel bowl or another pan.) The top container must fit snugly into the lower one so that steam or sputtering water won’t mix with the chocolate (this would seize the chocolate, separating the sugars from the proteins and fats, ruining it for most purposes, and it is very hard to reverse.) Water is boiled in the lower container, the top container holds the chocolate. The top container sits just above (not in) the boiling water. Make sure not to boil the lower container dry.

Stages of cooked sugar syrup:
Most experienced candy makers use both a a thermometer and a physical test.

Spoon test:
Use a clean wooden or silicone spoon to lift a small quantity of the syrup up out of the pot and drop back into the pot.
Pearl - 220 - 222F104 - 105C. Runs off a spoon in drops.
Blow - 220 - 234F104 - 112C. Makes a loose thread that runs off the end of the spoon.
Thread - 230-F110C. Makes a brittle thread that runs off the end of the spoon.

Chilled water test:
Remove pan from heat.
Use a clean wooden or silicone spoon to drop a small quantity of the syrup (about 1/2 tsp) into a small container.
Quickly gather the syrup between your fingers.
Soft ball - 234F112C. Makes a limp, sticky ball that flattens when removed from the water and rolled between the fingers.
Firm ball - 244 - 248F118 - 220C. The ball will hold its shape and will not flatten unless pressed with fingers.
Hard ball - 250 - 266F121 - 130C. The ball is more rigid, but is still pliable.
Soft crack - 270 - 290F132 - 143C. The syrup will separate into hard threads, which when removed from the water will bend.
Hard crack - 300 - 310F149 - 154C. The syrup separates into threads that are hard and brittle.

Colour test:
310 - 338F154 - 170C. Syrup changes from honey coloured to light brown.
356F180C. Syrup becomes medium brown.
374F190C. Syrup becomes dark brown - this is only used to colour sauces.
410F210C. Syrup becomes black - this has no use.

Toasting and Grinding Spices:
Toast spices in a dry skillet and shake the seeds over medium-high heat until they release an intense aroma (about 4 minutes).
Traditionally spices are ground using a mortar and pestle. I use a coffee grinder (reserved for this purpose alone, unless I want spicy coffee, or coffee-flavoured spices) to pulverize my spices and seeds before adding them to recipes.