Preheat oven to 350°F.
Season the chicken thighs with sea salt and pepper on both sides.
In a cast iron or covered cast iron skillet, add the two tablespoons of olive oil medium-high heat.
Add the chicken thighs to the skillet skin side down. Brown skin side down for about 6 minutes, flip, and brown other side for an additional 6 minutes. Remove and set aside.
Using the same skillet, remove excess oil from the bottom, leaving a nice coating at the bottom of the skillet. Add the finely chopped fennel, finely chopped onions, and minced garlic to the skillet. Season with sea salt and pepper. Sauté until onions are soft and translucent.
Deglaze the pan with the white wine or chicken stock.
Add the orzo to the skillet and cook for 2-3 minutes or until orzo has a nice golden-brown color.
Using the whole lemon, zest it over the skillet. With the same lemon, slice six thin lemon rounds using about half of the lemon. With the remaining half of lemon, juice it into the skillet.
Add 1 ¾ cups of chicken broth to the skillet and bring to a low boil. Add the browned chicken thighs skin side up, cover skillet and place in preheated 350° oven for 35-40 minutes or until orzo is tender.
*If you like a more brothy consistency, at the end baking, remove the chicken, and an extra cup of chicken stock to the skillet, stir to combine and serve. Easy and flexible to suit your taste.
Garnish with lemon slices and serve.