While chicken is still on the cutting board, pat it dry and season with ½ teaspoon salt, ½ teaspoon paprika and ½ teaspoon pepper.
Heat 2 tablespoons olive oil in a 3.75 or larger braiser (this is the one I use) or Dutch oven over medium high heat. Add chicken and cook until most off the chicken is opaque (chicken will not be cooked through). Remove to a plate.
Melt the butter in the drippings and heat over medium-high theat. Add onions and sauté for 4 minutes. Add orzo and sauté for 2 minutes. Add the grated zucchini and garlic and cook an additional 2 minutes or until the onions are tender.
Stir in the evaporated milk. Whisk the chicken broth with the cornstarch in a liquid measuring cup (or bowl) and add to the pot. Add the remaining ingredients up to "Add Later" (lemon juice, lemon zest, chicken bouillon, salt, pepper and thyme). Stir the chicken back into the pot.
Cover the pot and bring to a simmer. Reduce heat to medium-low and simmer for 8-10 minutes, or until orzo is tender, stirring every couple minutes so the orzo doesn’t burn on the bottom, and replacing the lid. Add additional broth if the orzo isn't done and most of the liquid is absorbed. (The finished orzo has more of a risotto consistency - all of the liquid will likely not be absorbed.)
Stir in the mozzarella cheese until melted followed by feta and fresh herbs. Taste and season with additional lemon juice, salt and pepper. If desired, you can make the dish "saucier" or creamier by stirring in additional broth, milk or cream.
