Prepare the Base: Preheat the oven to 375°F. In a 9 x 13 casserole dish, combine the orzo, sun-dried tomatoes, onion, garlic, lemon zest and juice, Dijon mustard, Italian seasoning, kosher salt, cracked black pepper, and heavy cream. Stir until everything is well mixed. Then, stir in the chicken stock and place the spinach on top. Press it into the cream mixture.
1 1/4 cup dried orzo, 1/2 cup chopped sun dried tomatoes, 1/2 yellow onion, diced finely, 8 cloves garlic, minced finely, 1 small lemon, juiced & zested, 1 Tablespoon dijon mustard, 2 teaspoons italian seasoning, 1 teaspoon Morton kosher salt*, fresh cracked black pepper, 1 cup heavy cream, 1 5-ounce clamshell fresh spinach, 3 cups chicken stock or broth