Preheat oven to 375°F (190°C).

Heat 1 tbsp olive oil in a skillet over medium heat. Sauté minced garlic for 30 seconds, then add spinach. Cook until wilted (2 mins). Remove from heat and mix in cranberries and half the thyme.

Cut a horizontal pocket into the thickest part of each chicken breast, being careful not to cut all the way through.

Stuff each breast with equal parts Brie slices and the spinach-cranberry mixture. Secure the opening with toothpicks.

Season the outside of the chicken generously with salt, pepper, and remaining thyme.

Heat remaining 1 tbsp olive oil in the skillet over medium-high heat. Sear chicken for 4-5 minutes per side until golden brown.

Transfer skillet to oven (or move chicken to a baking dish) and bake for 15-20 minutes, or until internal temperature reaches 165°F (74°C).

Optional: Remove chicken to rest. Add broth, vinegar, and honey to the hot pan; simmer 2 mins. Whisk in cold butter for a sauce.

Remove toothpicks before serving.