Preheat oven to 400F.
Combine tomatoes, coconut milk, salt and diced onion in small saucepan.
Cook, uncovered over medium heat, stirring occasionally 25 to 35 minutes or until thick.
Heat oil in medium skillet; add sliced onion cooking 15 to 20 minutes until caramelized. Add bell pepper slices, cook, stirring 5 minutes longer.
Spread tomato-coconut sauce over pizza crust. Arrange cheese, onion-bell pepper mixture, pineapple tidbits and macadamia nuts evenly over crust.
Bake 20 to 25 minutes or until nicely browned.