Toss chicken with 2 tbsp (30 mL) barbecue sauce in large bowl. Place skin-side down on grill preheated to medium-high. Cook with lid closed, about 15 min. Turn chicken pieces over. Cook about another 10 min until chicken is cooked through, or instant-read thermometer registers 165°F (74°C) in thickest part of chicken. Remove from grill.
Meanwhile, in large serving bowl, whisk together lime juice, olive oil and cumin. Add black beans, red pepper, onion and cilantro. Set aside.
Remove and discard skin and bones from chicken. Shred meat; mix with remaining 2 tbsp (30 mL) barbecue sauce.
Toss spinach with bean mixture. Divide onto 4 plates. Top with chicken mixture and garnish with extra cilantro. For added flavour, serve topped with sliced avocado, shredded pepper jack cheese and crushed tortilla chips.
Substitute 2 cups (500 mL) leftover cooked chicken or turkey for chicken thighs.