Heat oven to 200 degrees

Put the chopped jalapeños, vinegar and sugar in a small bowl, mix to combine and dissolve the sugar, then set aside to pickle.

Place the corn, cream, polenta, 2 of the garlic cloves, the egg, 1 Tablespoon of the olive oil, ¾ teaspoon of salt and a generous grind of pepper in a food processor. Pulse to a very rough puree (you want to see some of the corn pieces still a bit chunky), then transfer to a bowl and mix in the cheeses.

Use a small, sharp knife to make a lengthwise incision in the peppers taking care not to cut through to the ends. You want it to open like the top of a pocket book which will take a little encouraging. Use your fingers or a small spoon to gently remove and discard the ribs and seeds. Stuff each pepper with the corn mixture, making sure to get it into all the nooks.

Put a Tablespoon of the olive oil in a large Dutch oven, top with the onion rounds and thyme. You want the onions to cover the base of the pan to protect the peppers from the direct heat. Sprinkle them with a pinch of salt and more pepper.

Lay the stuffed peppers slit side up on top of the onions and drizzle over a Tablespoon of oil. Season lightly with salt and pepper and then pour 200 ml of water into the pan, making sure not to pour it over the peppers.

Bake in the center of the oven for 30 minutes, then turn up the heat to 220 degrees and bake for 20 minutes more, until the peppers and onions are soft and nicely colored.

Meanwhile, in a small bowl, mix the remaining 4 Tablespoons of olive oil with the cilantro, remaining garlic that you should mince, a pinch of salt and some freshly ground black pepper. Add some red chili flake if you'd like it even spicier.

When the peppers are ready to serve, drizzle with the oil and garnish with the pickled jalapeño. Serve warm.