Place a wok or a large skillet, over medium heat and add the beef, black pepper, and chili flakes. Cook it breaking up the meat with a wooden spoon until browned, about 4-5 minutes.
Next, add the butter, garlic, and ginger, stir, and cook for 2 more minutes, until the beef gets crispy.
After that, add the bell pepper chunks and 1 cup pineapple chunks.
Also, add the soy sauce, and sweet chili sauce, stir, and cook until the sauce coats the beef, 2-3 minutes.
Mix in the green onions and sesame seeds. Remove from the heat.
In a medium bowl, toss the remaining 1 cup pineapple chunks with the chopped cilantro, basil, lime juice, and peanuts.
Serve the beef over bowls of rice and top with the pineapple cilantro salad. Enjoy!