Season and grill or pan-sear the chicken until fully cooked; rest and dice.
In a bowl, whisk together cottage cheese, Greek yogurt, and ranch seasoning (add little water/milk if needed to make a pourable sauce).
Stir BBQ sauce into that mixture (reserve some for drizzle).
In serving bowls, layer your base (rice or greens + beans + corn). Top with diced chicken.
Drizzle BBQ-ranch sauce over, sprinkle cheddar, optionally heat to melt cheese lightly.
Garnish with tomatoes, green onions, cilantro. Serve immediately.