Boil the peeled and washed potatoes in salted water until tender. Mash with a fork, incorporate the heavy cream, and season to taste.
Peel the carrot and celeriac, then cut into fine julienne strips along with the zucchini. Blanch briefly, drain, refresh in ice water, and reserve.
Cut the pastry sheets into diamond shapes. Brush with melted butter and brown under a salamander broiler.
Braise the beef cheeks in a seasoned court-bouillon flavored with coarse salt and gray peppercorns for about 3 hours, until the meat shreds easily with a fork. Shred the meat and keep warm.
Toast the mignonette grise in a knob of butter. Deglaze with a splash of the braising broth, reduce by three-quarters, infuse with saffron filaments. Mount the sauce with remaining butter over low heat for silky texture. Season, then fold in finely chopped herbs.
Place a dome of mashed potatoes in the center of each plate. Build layers: pastry diamond, shredded beef cheek, pastry diamond, vegetable julienne, finishing with a pastry diamond on top.
Surround with the saffron-fine herb sauce.
A signature creation by Chef Hubert, drawing on years of fine dining expertise.
