Tuna & Quinoa Salad

Mild and quick. The white part is stronger; the green tops are softer and often scattered over at the end.

1. Trim off the hairy root and any tired tips of the green.
2. Line them up together and slice across into thin rings, or slice long thin strips at an angle.

The zest (the coloured skin) holds the fragrant oils; the white pith underneath is bitter.

1. Zest first, while it is whole: rub it over the fine side of a grater, turning as you go, taking only the coloured layer.
2. To juice, roll it firmly on the worktop under your palm, cut it in half across the middle and squeeze over your cupped hand or a sieve to catch the pips.

Ring-pull lids have razor-sharp edges once open.

1. Pull the ring slowly and steadily towards you, keeping fingers away from the lid's edge.
2. Don't press food down with your fingers inside an open tin — use a spoon.

Rinsing washes off loose starch (so rice is less sticky), dust and grit (lentils), and the salty, starchy liquid in a tin of beans.

1. Tip it into a sieve and hold it under the cold tap.
2. Swish it around with your hand for about 30 seconds, until the water running out is mostly clear.
3. Shake off the excess water before it goes in the pan.

A boil is big bubbles rolling hard across the whole surface. A simmer is much gentler: small bubbles rising lazily, a few breaking the surface. Stews, sauces and soups simmer; boiling makes meat tough and sauces catch on the bottom.

1. Bring it up to the boil on a higher heat, then turn the heat down until the bubbling calms to a gentle simmer.
2. Check every few minutes and adjust — a lid on makes it hotter, a lid off lets it thicken.
3. Stir now and then, scraping the bottom, so nothing sticks and burns.

Ready when: Small, steady bubbles — not a still surface, not a rolling boil.