In a small pot of boiling water, cook the wheat berries until tender, 20 to 40 minutes. Drain and spread out on a plate to cool.
In a small skillet, toast the wheat berries until golden and crunchy, 7 to 8 minutes.
Meanwhile, in a small saucepan, melt the butter. Cook over medium heat until golden brown and nutty-smelling, 5 to 7 minutes.
In a large nonstick skillet, heat the oil until shimmering. Season the halibut with salt and pepper and cook over moderately high heat until browned on both sides and just cooked through, 3 to 4 minutes per side. Transfer to a plate.
Add the celery, scallions, and dried chili to the skillet and cook, stirring for one minute. Add the brown butter, lime juice, and Red Boat Fish Sauce and cook until the sauce is slightly thickened, about 2 minutes. Add the fish and turn to coat in the sauce. Discard the dried chili.
Transfer the fish and sauce to a platter and garnish with some of the toasted wheat berries. Serve with rice.