Preheat your oven to 200°C (180°C fan) and lightly grease a 23x33cm (9x13 inch) baking dish.

Pat the chicken thighs dry with a paper towel and season them generously on both sides with salt and pepper. This is a key step for ensuring the chicken itself is well-seasoned.

In a small bowl, whisk together all the sauce ingredients: honey, wholegrain mustard, Dijon mustard, apple cider vinegar, soy sauce, and thyme. Set it aside for a moment.

Heat the olive oil in a large, oven-safe frying pan or skillet over a medium-high heat. Once hot, add the chicken thighs, ensuring you don't overcrowd the pan (work in batches if needed). Sear for 3-4 minutes per side, until they are beautifully golden brown. The chicken won't be cooked through at this point.

Remove the chicken from the pan and place it in your prepared baking dish.

Reduce the heat to medium. Add the chopped onion to the same pan and sauté for 4-5 minutes until softened. Add the minced garlic and cook for another minute until fragrant.

Pour the prepared honey mustard sauce into the pan with the onions and garlic. Bring it to a gentle simmer, scraping up any browned bits from the bottom of the pan. Let it bubble for 1-2 minutes until it has slightly thickened. What works best for me is tasting the sauce at this stage and adjusting seasoning if needed.

Pour the warm sauce evenly over the chicken thighs in the baking dish.

Bake for 20-25 minutes, or until the chicken is cooked through and the internal temperature reaches 74°C (165°F). The sauce should be bubbly and caramelised at the edges. For an extra sticky glaze, you can spoon some of the sauce from the bottom of the dish over the chicken halfway through baking.

Remove from the oven and let the chicken rest for 5 minutes before serving. Garnish with fresh parsley, if you like.