Difficulty: 3/5
Melt the butter in the microwave or over low heat. Skim off the foam from the surface, retain the thick yellow liquid, and discard the whey at the bottom (clarified butter). Reserve.
Finely grate the celeriac, blanch for 30 seconds in boiling salted water, drain, and refresh under cold water.
Make a thick mayonnaise: whisk egg yolk, mustard, salt, and pepper. Gradually add grapeseed oil in a thin stream until set. Stir in cream and half the grapefruit juice. Fold in the celeriac thoroughly.
In a pan, combine reserved clarified butter and remaining grapefruit juice. Sear scallops 3 minutes per side. Season with fleur de sel and white pepper.
Serve immediately: celeriac remoulade in the center, scallops around, garnished with chervil sprigs.
