Pour water into a large wide frying pan or saucepan to 5cm-deep. Put over a high heat and bring to the boil. Reduce heat to a low (so there are a few small bubbles breaking on the surface). Add salt and white vinegar.
2.
Break 1 egg into a cup. Use a spoon to swirl water in pan, creating a vortex, then carefully slide egg into water. The egg will swirl, forming a circular shape.
3.
Repeat with remaining eggs. Poach, in 2 batches, for about 2 minutes for a runny yolk, 3 minutes for a soft yolk and 4 minutes for a firm yolk.
4.
Line a plate with paper towel. Using a slotted spoon, transfer eggs to prepared plate to drain. If there are any stringy-looking pieces of eggwhite, cut them off using a small knife.
5.
Serve poached eggs on toast, seasoned with salt and pepper.