In small bowl, whisk together hoisin sauce, vinegar, soy sauce, honey, sesame oil, chili sauce, ginger, and peppercorns, if using. Place half the sauce in separate bowl.
Build a medium-hot fire in a charcoal grill, or heat a gas grill to medium-high. Brush skin side of salmon with oil. Brush half the sauce on salmon. Place salmon on grill grates, skin side down; close grill cover and heat until fish is just barely cooked through in the center, about 8 minutes. Remove fish from grill; let rest 5 minutes, then gently break apart flesh into 1 inch chunks.
As salmon cooks, finely chop broccoli florets and add to large bowl with cilantro and green onions. Peel broccoli stalks to remove tough skin and thinly slice; add to bowl with broccoli. Add remaining sauce and massage sauce into broccoli until tender.
Grill tortillas for 1 minute per side, until just slightly charred. Watch tortillas closely, as they’ll burn very easily.
Top tortillas with salmon, broccoli slaw, and peanuts.