Make the marinade. Whisk together orange juice, soy sauce, coconut aminos, miso, ginger, honey, garlic, black pepper, chili flakes, and rice vinegar until smooth.
Slow cook. Place roast in slow cooker and pour marinade over.Cook on low 8–9 hours or high 5–6 hours until tender.
Shred the beef. Remove and shred with two forks. Return to juices if desired.
Crispy oven finish. Spread beef on a sheet pan, toss with a little cooking liquid + squeeze of lime.Bake at 425°F for 10–15 minutes, tossing halfway. Optional: broil 1–2 minutes for extra crisp.
Make the brussels slaw. Toss shaved brussels with lemon + lime juice, olive oil, and salt. Let sit 5–10 minutes, then add cilantro.
Serve. Plate with mashed potatoes, crispy beef, roasted carrots, and slaw. Finish with fresh herbs and citrus zest.