Extra time:5min ›
- To make the hollandaise sauce, whisk together the egg yolks, mustard and yoghurt in a heatproof bowl.
- Set the bowl over a saucepan of barely simmering water and cook for about 12–15 minutes, stirring constantly, until thick: the sauce will become thinner at first, but will then start to thicken. Stir in the chives, and season with pepper. Remove from the heat and keep the sauce warm over the pan of hot water.
- Half-fill a frying pan with water. Bring to the boil, then add the vinegar. Reduce the heat so the water is just simmering gently, then carefully break the eggs into the water, one at a time. Poach for 3–4 minutes, spooning the hot water over the yolks towards the end of cooking.
- Meanwhile, preheat the grill to high. Lightly toast the muffin halves for about 1 minute on each side. Place one half on each of 4 warmed plates and top each with a slice of prosciutto, crumpled slightly to fit. Season with pepper.
- Using a slotted spoon, remove the poached eggs from the pan, one at a time. Drain on paper towel and, if desired, trim off any ragged edges of egg white with scissors. Place an egg on each prosciutto-topped muffin half.
- Spoon the warm hollandaise sauce over the eggs, and sprinkle each serving with a pinch of paprika and the chives. Serve immediately with the remaining toasted muffin halves.
• Instead of chives, add 1 tablespoon chopped fresh tarragon to the hollandaise, and garnish with sprigs of tarragon.
• You can also use thin slices of lean cooked ham instead of prosciutto.
Like other animal foods, eggs provide useful amounts of vitamin B12. Free-range eggs tend to contain more than eggs from battery hens. All the fat in eggs is found in the yolk (around 6 g per average-sized egg) and is predominantly unsaturated fat.