Learning to poach eggs will serve you for many years to come. It may take you a time or two to get the poaching right (see technique, below), but before long, you’ll master the firm whites and runny yolks that are the hallmarks of perfectly poached eggs, coveted by brunch aficionados. For a new way to enjoy poached eggs, try them over toast with mackerel fillets in mustard.
thick slices sourdough bread, about 1 inch thick
(60 milliliters) extra-virgin olive oil
(120 grams) sour cream
Kosher salt and freshly ground black pepper
large eggs, the fresher the better
4.4-ounce (125 grams) tins mackerel in whole-grain mustard
Small handful of arugula or watercress
Lemon, for squeezing
Fill a small saucepot three-quarters of the way with water. Add the vinegar and bring to a boil. The vinegar will help the egg whites hold their shape.
While waiting for the water to come to a boil, drizzle both sides of the 4 slices of bread evenly with the olive oil. Toast the bread under your broiler or on a griddle. You want some color but still want the bread to be soft in the middle. In a small bowl, mix together the mustard and sour cream. Season with salt and pepper.
Turn the water down to a gentle simmer. One at a time, crack an egg into a small bowl and carefully slide the egg into the water. Gently give the water a stir two or three times. This helps the eggs to cook evenly. Allow the eggs to simmer for 3 minutes for runny yolks or 5 minutes if you prefer them a bit firmer.
Evenly spread the mustard mixture on the toasted bread. Top each piece of toast with a half tin of mackerel. Using a slotted spoon, remove the eggs one at a time and place one on each piece of toast and season with salt and pepper. Top with a few leaves of arugula or cress, squeeze on a little lemon juice, and serve.