Fry bacon lardons in a wide pan over medium heat to release the fat; scoop up lardons and drain on kitchen roll.
Add the beef to the pan; cook and stir until browned. Mix in onions, garlic and chilli pepper; cook until fragrant. Stir in leeks and tomatoes; add bacon lardons back into the pan.
Stir in vinegar, cloves, cardamom, dried chilli flakes and bay leaves; add tomato puree and crumble the stock cube on top. Pour in enough cold water to cover the ingredients; simmer, covered, over low heat for 2 hours.
Add green beans and plantains; continue to simmer for 20 minutes. Stir in pineapple and simmer til heated through.
Mix cornflour with a little water until smooth; stir into stew until thickened slightly.