You have to peel the pineapple first. Remove the leafy crown from the head using the knife. Peel the skin of the fruit like you are peeling a large apple. Remove all traces of the wooden core. Slice the pineapple thinly using your hands, knife or the slicing attachment that comes with the food processor. If you think this is too much of an effort you can buy canned pineapple slices from the market. However, you might miss out on the fresh part here.
Peel the mango. Use a grater to grate roughly into a separate bowl. By now you should have two bowls, One of pineapple slices and the other of mango slices. Mix the shallot with the pineapple now.
Make the dressing now by whisking together lemon and olive oil in a small mixing bowl. Season with salt and freshly ground pepper. Pour half of this dressing in the mango bowl and the other half in the pineapple bowl. Toss the fruits so that the dressing is coated well.
Take out individual platters. Divide the mango among them and sprinkle some chilli powder over them. Now add the pineapple, arranging to the sides of the mango. Serve right away.