White and Green Asparagus with Sauce Maltaise

Peel the asparagus and snap off the woody ends. 

Bring a large pot of water to a boil with the salt, butter and sugar. Cook the white asparagus for about 10 minutes over low heat. Add the green asparagus and cook for another 10-15 minutes, until tender.

For the sauce: Finely grate the zest of the blood orange then peel and squeeze out the juice. Melt the butter in a saucepan and skim off the foam. Add the wine and vinegar and let boil down to about 2/3 of the original volume. Let cool then transfer to a bowl and whisk in the egg yolks. Transfer to a hot water bath and whisk until creamy. Slowly whisk in the melted butter, by the drop at first then in a thin steady stream, until creamy. Mix in 1/2 of the zest and season to taste with the blood orange juice, salt and pepper.