1wholehead of garlic, cloves separated and peeled*
Preheat the oven to 400°
Arrange the mushrooms, broccolini, bell peppers and onion on a rimmed baking sheet and drizzle with olive oil.
Heat the ghee in a large skillet over medium-high heat. Season the chicken on both sides with a little salt and pepper. Add the chicken, garlic cloves, and rosemary springs to the pan. Sear the chicken on both sides until the skin is crispy and golden brown. (The chicken will not be fully cooked at this stage.) As the garlic starts to brown, remove it from the pan and place it on the baking sheet with the vegetables. Do the same with the rosemary springs.
Place the chicken thighs on top of the vegetables and pour any pan drippings over the top of everything.
Transfer the baking sheet to the oven and bake the chicken and vegetables for 20 minutes., until the chicken is cooked through and the vegetables are tender but not mushy.
* To make this low fodmap, I used more bell peppers and sliced zucchini in place of the broccolini and mushrooms. I used 2 tablespoons of garlic oil instead of the fresh garlic. I topped it with chopped green onion in place of the red onion.