Peel and roughly dice the onion. Clean, peel and quarter the pineapple and cut out the stalk. Cut the pineapple into pieces. Heat oil in a pan and fry bacon.
Add onion and pineapple and fry for 2-3 minutes. Add baked beans, bring to the boil. Season to taste with salt, pepper, chili flakes and marjoram. Let simmer for about 5 minutes.
Wash the parsley, shake dry. Pluck off leaves and chop. Sprinkle over the baked beans and serve.