01 -
Get your oven warmed up to 200°C (180°C if you're using a fan oven). Meanwhile, carefully cut a pocket into the side of each chicken breast. Don't go all the way through. Sprinkle the insides and outsides with half the salt and pepper.
02 -
Melt the butter in a heavy pan that's safe for the oven. Turn the heat high, toss in the mushrooms, and let them cook for around 3 minutes till they start to brown. Add the garlic, thyme, and the rest of the salt and pepper, stirring for another 2 minutes. Mix in your spinach just until it softens, which will only take about 30 seconds.
03 -
Stuff the pockets in the chicken with your cooked mushrooms. Lay the cheese over the top of the filling. Use toothpicks to loosely close the opening; don't worry about sealing it completely, just keep the filling mostly secure.
04 -
Quickly wipe out your pan with a bit of paper towel. Heat olive oil on medium-high, then brown the stuffed chicken on both sides for about 90 seconds each until golden.
05 -
Pop the pan with the browned chicken into your heated oven. Bake for roughly 15 minutes, or until the inside temperature hits 65°C. Make sure you're checking the meat, not the cheesy filling.
06 -
Take the chicken out of the oven and onto a plate. Loosely cover it with foil and let it sit for 5 minutes. Serve it warm—pairing it with creamy lemon and herb risotto and spinach drizzled in balsamic vinaigrette would be awesome.