Peel the pineapple and cut into thick rings, peel the onion and cut into thick rings. Mix the olive oil with a little salt and pepper and pour over the pineapple and onion rings. Work very carefully so that the onion rings stay whole.
Preheat the grill and grill the pineapple slices for about 5 minutes on each side. Also grill the onion rings until they are soft.
Then the pineapple is quartered, if it is large it is better to divide it into 8 pieces. The onion rings are roughly chopped, put everything in a bowl. Chop the basil or leave the leaves whole and pour over the pineapple and onion rings.
Rub the lemon peel, squeeze out the juice. 1 tablespoon of olive oil is mixed with lemon juice, lemon zest and sugar. Pour the dressing over the salad and stir well. Season again to taste.
The salad tastes best when it has time to pull something through.