Preheat the barbecue to medium-high heat (about 220°C – 425°F).
Place a pizza stone on the hot grill and close the lid. Heat the stone for 13 to 15 minutes.
Meanwhile, heat half of the oil in a saucepan over medium heat. Sauté the onions for 4 to 5 minutes.
Add the maple syrup, balsamic vinegar, and thyme. Season with salt and pepper. Bring to a boil, then reduce heat to medium and simmer for 8 to 10 minutes, stirring regularly, until the onions are caramelized. Remove from heat and set aside.
In a frying pan, heat the remaining oil over medium heat. Cook the duck bacon for 4 to 5 minutes.
Add the kale to the pan and continue cooking for 2 to 3 minutes. Add the sun-dried tomatoes. Season with salt and pepper, and stir. Remove from heat.
On a lightly floured surface, stretch the pizza dough into a 30cm (12 inch) diameter circle. Place the dough on a pizza pan or a wooden board.
Top the pizza with the caramelized onions and the bacon mixture, leaving a small border. Cover with cheese.
Carefully slide the pizza onto the hot pizza stone. Close the barbecue lid and cook for 10 to 12 minutes.