Fill a large pot with water, add a generous pinch of salt, and bring it to a boil. Add 8 ounces of penne pasta and cook according to the package instructions until al dente. Reserve about 1/2 cup of pasta water, then drain the pasta and set aside.
Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add the cubed chicken breast and season with salt and pepper. Cook for about 5-7 minutes until golden brown and cooked through, stirring occasionally. Remove chicken from skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 1 minute until fragrant, taking care not to burn it. Add halved cherry tomatoes, dried basil, and dried oregano. Cook for 3-4 minutes until tomatoes soften and release their juices, stirring occasionally.
Stir in the fresh spinach and cook until wilted, about 2 minutes. Return cooked chicken to the skillet and toss everything together.
Add the cooked penne into the skillet with the chicken and vegetables. Pour in a splash of the reserved pasta water to help everything blend smoothly. Stir in the grated Parmesan cheese until melted and creamy. Adjust seasoning with salt and pepper as needed.
Plate your Tuscan Chicken Penne with Spinach and garnish with fresh basil leaves. Serve immediately for a warm, satisfying meal.