Preheat oven to 400 degrees F. Dice pancetta and sauté in a hot pan until almost crispy. About 5 minutes. Spoon onto a plate and set aside.
Take chicken breasts and season both sides with salt and pepper. Place in a 9×13 baking dish.
Remove rosemary from springs and cut in 1/2.
Using a small bowl add salt, pepper, rosemary, garlic and lemon juice. Combine well then rub over the chicken. Add to baking dish.
Take brussel sprouts and place in a medium bowl. Season with salt and pepper. Surround chicken with brussel sprouts.
Drizzle olive oil over chicken and brussel sprouts. Add slices of lemons.
Bake in oven for 20-25 minutes, until the chicken is cooked and skin will be crispy.
Add pancetta into the baking dish about 5 minutes before the chicken is done. Serve right out of the baking dish!
Enjoy!