Remove the stalk from the pineapple, then peel thoroughly. Cut the pineapple lengthwise into quarters, then remove the hard core. Finely dice the pineapple, collecting any juice created in a bowl.
Rinse the chili peppers, remove the seeds, and julienne. Peel and finely dice the onion. Rinse, trim, and thinly slice the scallions. Mix the pineapple with the sugar and the lemon juice. Add the chili peppers, scallions and onions and mix until combined. Place in jars, and let infuse for at least 24 hours.