Gut the mackerels, remove the heads, rinse under cold water, pat dry, and season with freshly ground black pepper.
Mix the green peppercorns with half the mustard. Coat the inside of each fish, add half the finely chopped herbs, and wrap in aluminum foil to form papillotes.
Bake for 15 minutes.
Mix the cream with the remaining mustard and warm gently over low heat.
Off the heat, stir in the remaining chopped herbs.
Cook the rice according to package instructions.
Unwrap the mackerels, sprinkle with the remaining fine herbs, lightly crushed pink peppercorns, and more black pepper. Serve atop the rice.
Finish with the warm mustard cream sauce.
A signature creation by Chef Hubert, blending fresh seafood with Provençal herbs for an authentic, restaurant-quality dish.