Follow these simple steps to prepare Tuscan Butter Beans with Spinach and Sun-Dried Tomato:

1. Heat Olive Oil: In a large skillet over medium heat, add the olive oil. Once hot, add the diced onion and sauté until it becomes translucent, about 3-4 minutes.
2. Add Garlic: Stir in the minced garlic and cook for an additional 1-2 minutes until fragrant.
3. Incorporate Sun-Dried Tomatoes: Add the chopped sun-dried tomatoes to the skillet, mixing them in with the onion and garlic. Cook for another 3 minutes.
4. Add Butter Beans: Gently fold in the drained butter beans, being careful not to mash them.
5. Pour in Vegetable Broth: Add the vegetable broth, dried oregano, and red pepper flakes if using. Bring the mixture to a simmer.
6. Add Spinach: Once simmering, stir in the chopped spinach until it wilts down, approximately 2-3 minutes.
7. Season: Taste and season with salt and pepper as desired.
8. Finish Cooking: Allow the mixture to cook for an additional 5-10 minutes until heated through and flavors meld together.
9. Garnish and Serve: Remove from heat and garnish with fresh basil. Serve hot.

By following these steps, you will create a vibrant and wholesome dish that embodies the heart of Tuscan cooking.