Season the chicken thighs on both sides with salt, pepper, and Italian seasoning.
Heat the olive oil in a large skillet over medium-high heat. Add the chicken and cook for 5 to 6 minutes per side until golden brown and cooked through. Remove the chicken from the skillet and set aside.
Reduce heat to medium. Add the minced garlic and sun-dried tomatoes to the same skillet. Cook for about 1 minute, stirring frequently, until the garlic is fragrant.
In a small bowl, whisk the cornstarch into the chicken broth until smooth. Pour into the skillet along with the heavy cream. Stir well and bring to a gentle simmer.
Cook the sauce for 3 to 4 minutes, stirring often, until it thickens enough to coat the back of a spoon. Stir in the parmesan cheese until melted and smooth.
Add the baby spinach and stir until it wilts into the sauce, about 1 to 2 minutes.
Return the chicken to the skillet and spoon the creamy tuscan sauce over the top. Let everything simmer together for 2 minutes to warm through. Garnish with fresh basil and serve over rice, gluten free pasta, or with crusty gluten free bread.