Heat the olive oil in a large skillet over medium-high heat.
Add the ground beef and cook until browned, breaking it up with a spoon as it cooks.
Drain any excess fat and return the skillet to the heat.
Add the chopped onion, green bell pepper, and garlic to the skillet with the beef. Cook, stirring, until the vegetables are tender, about 5-7 minutes.
Season with salt and pepper.