In a dry skillet over med heat, place mustard seed, fennel, coriander, cumin, and peppercorns. Keep moving skillet, to keep the seeds from burning; cook until aromatic, about 2 minutes. (mustard seeds will begin to pop).
Transfer to a spice grinder, or use a mortar and pestle to finely chop the spices, but do not grind completely to a powder. Transfer to a small bowl and add the thyme, dry mustard, ginger, 1/2 tsp salt, and sugar. Set aside.
Heat oven to 425°F Rub pork with 1 Tbsp Dijon mustard, sprinkle with 1/2 tsp salt and 2 Tbsp spice mixture.; pat with hands to stick. Spray a small roasting pan with cooking spray and place pork in pan.
Bake about 25 minutes, transfer to cutting board and let rest covered loosely with foil.
Place roasting pan on stove over med-high heat, stir in wine and deglaze the pan. Stir in chicken stock. Cook, stirring occasionally, until reduced by half, about 5-7 minutes.
Whisk together flour and 1/4 cup water, then whisk into the sauce. Whisk in remaining tablespoon Dijon mustard; cook until mixture thickens, 2-3 minutes. Stir in the berries; cook until they begin to soften, about 2 minutes.
Slice pork, transfer to a platter, and serve with the sauce. Garnish with fresh thyme if desired.