Season the cubed chicken with salt, black pepper, and 2 teaspoons of the Italian seasoning.
Heat the olive oil in a large skillet over medium-high heat. Add the chicken and cook, stirring occasionally, about 5 minutes until mostly cooked through.
Add the chopped shallot, chopped garlic, and butter to the skillet and cook until the shallot is softened, about 1–2 minutes.
Stir in the dry orzo, fresh thyme, and the remaining 2 teaspoons Italian seasoning; cook, stirring, until the orzo is lightly golden, about 2 minutes.
Pour in 1 1/2 cups water and bring to a boil. Reduce heat and simmer for about 5 minutes.
Stir in the milk or heavy cream and Dijon mustard, mixing until combined.
Add the quartered marinated artichokes, baby spinach, grated Parmesan, and lemon zest; cook, stirring occasionally, until the spinach wilts and the orzo is al dente, about 6–8 minutes.
Taste and adjust seasoning with chili flakes, salt, and pepper as desired, then serve topped with fresh basil and extra Parmesan if liked.