Asparagus spears with poached egg and tarragon butter

20 to 30 asparagus spears, trimmed
salt, to taste
1 tbsp white wine vinegar
4 eggs
100g butter
juice 2 lemons
2 tbsp chopped fresh tarragon
4 slices brioche, toasted

Steam the asparagus over plenty of boiling water for 3-5 minutes, depending on the thickness of the spears.

Bring a pan of salted water to the boil and add the white wine vinegar. Whisk to make a whirlpool. Once it's settled, crack an egg in the middle. Simmer for 2-3 minutes, remove and keep warm. Repeat with the other eggs.

melt the butter in a pan and stir in the lemon juice and tarragon. Pile the spears of asparagus onto each toasted brioche. Top with a poached egg, spoon on the butter sauce and serve.