Grilled BBQ Chicken Tacos

boneless skinless chicken breasts or thighs

homemade bbq sauce or store-bought, divided

cherry tomatoes, chopped

chopped red onion

black beans, rinsed and drained

corn, drained

avocado, peeled, cored and sliced

corn or small flour tortillas

Chopped cilantro, for topping

Creamy cilantro lime sauce:

plain Greek yogurt, or sour cream

chopped cilantro

lime juice

salt