Cook spaghetti according to package instructions until al dente; drain and set aside.
In a large skillet, heat olive oil over medium heat.
Add diced onion and sauté until translucent.
Stir in minced garlic and sliced bell pepper; cook for 2-3 minutes.
Pour in diced tomatoes and red wine, stirring to combine.
Add dried oregano and red pepper flakes; season with salt and pepper.
Bring the mixture to a simmer, allowing it to cook for about 8-10 minutes.
Toss the cooked spaghetti into the skillet, ensuring it is well-coated with the sauce.
Cook for an additional 2-3 minutes to heat through.
Serve hot, garnished with fresh basil.