Method

• 1.
  For the palm-sugar vinegar, crush the palm sugar and place in a saucepan. Moisten the sugar with 2 tbs water. Cook over medium heat, swirling pan occasionally, until sugar begins to caramelise, then turns dark and very fragrant. Be careful not to take it too far or it will burn.
• 2.
  Remove from heat and add vinegar (be careful; it will spit), then stir in the garlic and let it cool completely (see note).
• 3.
  Add the whole white and red onions to a large saucepan of boiling water. Cook at a gentle boil for 25 minutes, or until tender, then plunge into a bowl of iced water to cool. Blanch shallots in the same pan of boiling water for 1 minute, then add them to the iced water to cool. Transfer all onions to a clean tea towel to dry.
• 4.
  Meanwhile, light a charcoal grill or barbecue and let it burn down to glowing coals. Cut the white and red onions in half, then cut one of each of the halves in half again. Peel off the skin and discard, then separate the layers. Cut the roots from shallots, but otherwise leave them whole.
• 5.
  Lightly drizzle onions with olive oil, then season with salt flakes. Place on a rack set over the coals, or on the flatplate, and cook, tossing occasionally, for 2-3 minutes until onions are charred around the edges.
• 6.
  Transfer onions to a bowl and dress with 2 tbs palm-sugar vinegar. Add the extra virgin olive oil and lemon juice. Season and gently toss it all together with your hands. Pile the onions on top of the grilled pork chop to serve.