Saute the onions, tomatoes, garlic, flat leaf parsley, salt, and pepper in butter for approximately 4 minutes on high heat. Add prawns and saute for 30 seconds. Add white wine, cover for 2 minutes.
Lay bed of rice and grains on plate in small mound. Arrange prawns towards the center of the mound with tails out. Put 1/4 of butter sauce on each prawn, then add grilled pineapple brochette, garnish with Italian flat-leaf parsley and lemon.