Season both sides of the thighs. Heat oil in a large pan over medium-high heat. Add thighs & fry both sides until lightly charred/cooked right through the centre (4-5mins each side depending on size). If they start charring too aggressively just lower the heat slightly. Remove & place to one side. Lower heat to medium.
During this time finely dice the onion & garlic, halve the tomatoes & roughly dice the basil. If you need to grate the parmesan, make the stock & dice the chorizo do this now too (make sure it’s diced nice & small). If you run out of time you can do this as you fry the onions.
Add onion to the leftover fat in the pan & fry until it begins to soften. Add chorizo & fry for 2mins, then fry garlic for 30secs. Add wine, raise the heat & bring to a rapid simmer. Cook for around 2mins until it almost completely evaporates. Lower heat slightly.
Add stock, cream & parmesan & give it a really good stir to blend. Simmer fairly rapidly for 3-4mins until the sauce thickens, stirring frequently. Add tomatoes, basil & chicken resting juices & gently simmer for a couple of minutes until the tomatoes begin to soften.
Add chicken for a min or so to warm then serve!