1. Place a large frying pan over medium heat. Add the olive oil and butter,and once the butter has melted and is beginning to foam,add the onions. Turn the heat to low and sweat,stirring regularly. Sprinkle over the bicarb soda if using – this will help speed up the caramelisation process. Continue to cook,stirring regularly,until the onions have caramelised – about 30 minutes. Add the herbs and season with salt and pepper. Scrape the onions into a bowl and set aside while you prepare the chicken.
2. Preheat the oven to 170C fan-forced (190C conventional).
3. Return the frypan to the heat. Add the chicken thighs and cook until crisp and golden,about 3 minutes per side. Don't overcrowd the pan.
4. Scrape the onions into a large baking dish and spread them across the base. Nestle the chicken pieces into the bed of onions.
5. To a jug,add the wine,stock,mustard and sugar,and use a fork to give it a quick whisk. Pour this over the chicken and pop in the oven for 45 minutes. By this stage the liquid should have reduced,and you will have a slurpy onion base with beautiful crisp and soft chicken.
6. Sprinkle over the gruyere cheese and return to the oven for about 5 minutes.
7. While the cheese is melting,place a frypan over medium heat. Add the 3 tablespoons of butter,and once foaming,add the breadcrumbs and cook until lovely and crisp. Transfer to a bowl and combine with the parsley.
8. Remove the chicken from the oven,season with salt and pepper,sprinkle over the crouton mixture and serve.
More stews from Katrina Meynink