Poached egg, purple sprouting broccoli and tarragon hollandaise

Method

1. Melt the butter in a small jug and keep warm. Bring a deep frying pan of water to the boil, add a pinch of salt and a tiny splash of white wine or cider vinegar, then reduce the heat to just below a simmer.
2. Meanwhile, find a saucepan you can put 3-4cm water in and sit a heatproof mixing bowl over without the water touching the bowl. Add 3-4cm water to the saucepan and gently heat to a simmer.
3. Separate one of the eggs and put the yolk in the bowl with 1 tsp water (keep the white for another time). Put the bowl over the saucepan of water and use a balloon whisk to beat the yolk until it starts to become thick and mousse-like.
4. Remove the saucepan from heat, keeping the bowl set over it, and start to add the melted butter drop by drop, whisking all the time, until the mixture starts to emulsify. When it does, whisk in the butter in a thin stream to make a thick, glossy sauce. Whisk in 1-2 tbsp water from the simmering frying pan to thin it if necessary (this will also help bring it back together if your sauce happens to split).
5. Add a pinch of salt and a squeeze of lemon to taste, along with a tiny pinch of cayenne pepper and the chopped tarragon. Set aside (see Make Ahead).
6. Add more boiling water to the saucepan that was under the bowl, plus a good pinch of salt. Cook the broccoli for 3-4 minutes until just tender, then drain well.
7. Meanwhile, break the remaining 2 eggs, one at a time, into a cup and add to the gently simmering frying pan of water to poach. They should need 2-3 minutes for a set white and runny yolk. Remove with a slotted spoon and drain well.
8. Arrange the drained broccoli on 2 plates, top each with a poached egg and spoon over some of the hollandaise. Season and finish with a tiny pinch of cayenne. Serve with hot buttered sourdough too, if you like.