Citrus-Brined Pork Loin with Peach Mustard

• ½ medium onion, chopped
• 2 garlic cloves, peeled, crushed
• 1 bay leaf
• ½ cup kosher salt
• ¼ cup (packed) light brown sugar
• 1 teaspoon coriander seeds
• 1 teaspoon fennel seeds
• 1 teaspoon black peppercorns
• 1 orange, halved
• 1 lemon, halved
• 4 sprigs thyme
• 1 5-lb. center-cut bone-in pork loin, chine bone removed
• 1 tablespoon coriander seeds
• 1 tablespoon fennel seeds
• ¼ cup (packed) light brown sugar
• 2 tablespoons kosher salt
• 1 tablespoon coarsely ground black pepper
• 1 tablespoon paprika

Vegetable oil (for grilling)

Peach Mustard (click for recipe)

Mortar and pestle or spice mill

1. Bring onion, garlic, bay leaf, salt, brown sugar, coriander seeds, fennel seeds, peppercorns, and 2 cups water to a boil in a medium saucepan. Reduce heat and simmer, stirring, until salt and sugar are dissolved. Remove from heat and add 2 cups cold water. Transfer brine to a large heatproof bowl or jar. Squeeze orange and lemon juice into brine and add citrus halves and thyme. Chill until cool.
2. Place pork in a large resealable plastic bag and add brine. Seal bag, pressing out air, and chill at least 12 hours.
3. DO AHEAD: Brine can be made 2 days ahead; cover and keep chilled. Pork can be brined 24 hours ahead; keep chilled.
4. Remove pork from brine, brushing off any spices. Let stand at room temperature 1 hour before grilling.
5. Toast coriander and fennel seeds in a small skillet over medium heat, tossing occasionally, until fragrant, about 2 minutes. Let cool, then finely grind in mortar and pestle or spice mill; combine in a small bowl with brown sugar, salt, pepper, and paprika.
6. Prepare grill for 2-zone heat (for a charcoal grill, bank coals on 1 side of grill; for a gas grill, leave 1 or 2 burners off) and oil grate. Pat pork dry and rub all over with dry rub. Grill over direct heat, bone side
7. Transfer pork to cooler side of grill, bone side up; cover grill. Grill pork, turning occasionally, until an instant-read thermometer inserted into the center of loin registers 145°, 45–60 minutes. (The internal temperature of grill should be 400°; add more charcoal or adjust heat as needed.)
8. Transfer pork to a cutting board, tent loosely with foil, and let rest 20 minutes. Cut loin from ribs, and slice loin; cut between ribs. Serve with Peach Mustard.
9. DO AHEAD: Dry rub can be made 1 day ahead. Store airtight at room temperature.