In a bowl, toss the chicken cubes with kosher salt, black pepper, Italian seasoning, and smoked paprika. Then add the flour and mix to coat evenly.

Heat the olive oil and butter in a large skillet over medium heat. Add the chicken in a single layer and cook until golden brown and cooked through. Transfer the chicken to a plate and set aside.

In the same skillet, add the minced shallot and garlic. Sauté until soft, about 2 minutes. Stir in the sun-dried tomatoes and tomato paste, cooking for 1 minute. Pour in the chicken broth and heavy cream, stirring well. Bring the mixture to a simmer and let it cook for 3 minutes.

Add the tortellini, cover the skillet, and cook for about 3-5 minutes or until the tortellini are tender, stirring halfway through. Stir in the cooked chicken, spinach, lemon juice, and Parmesan cheese; cook until the spinach wilts, about 2 minutes. Adjust salt and pepper to taste and serve hot, garnished with fresh basil.