Preheat oven to 400F.
Heat avocado oil in a large, oven-safe skillet over medium-high heat. Season the chicken with paprika, Italian seasoning, dry English mustard, salt, and pepper. Sear chicken on both sides until a slight golden crust forms. Remove the chicken from the skillet and set aside.
Add the butter and shallot to the same skillet and sauté until softened. Next add the garlic and continue to sauté for another minute until fragrant.
Add the orzo pasta, chicken stock, dijon mustard, capers, and lemon juice. Stir, making sure to scrap up any bits at the bottom of the skillet.
Bring to a boil, then fold-in the half and half, spinach, and sun-dried tomatoes. Set the chicken back into the skillet and transfer the skillet to the preheated oven.
Bake uncovered for 15 minutes, or until the chicken has reached 165F.
Serve immediately with Italian Parsley and parmesan as a garnish.