Preheat the oven to 350°F (175°C).
In a large bowl, mix together lean ground beef, fresh basil, Italian seasoning, Parmesan cheese, and mozzarella cheese until well combined.
Cut the tops off the bell peppers and remove the seeds, leaving space inside for stuffing.
Fill each pepper half with the beef mixture, packing it in generously.
Arrange the stuffed peppers on a baking sheet, ensuring they have plenty of room.
Drizzle olive oil over the top of the stuffed peppers.
Bake in the preheated oven for about 45 minutes, or until the peppers are tender and the cheeses have melted and are bubbling.
Remove from the oven and let cool slightly before serving. Enjoy your delicious stuffed peppers!