Heat the olive oil in a large Dutch oven or heavy-bottomed pot over medium heat. Season the beef cubes with salt and pepper and add to the pot. Cook until the beef is browned on all sides, about 10 minutes.
Add the onion and garlic to the pot and cook until softened, about 5 minutes. Add the balsamic vinegar and tomato paste and stir to combine. Bring to a simmer and cook for 5 minutes.
Add the cherry tomatoes, oregano, basil, and red pepper flakes. Reduce the heat to low and cover the pot. Simmer for 30 minutes, stirring occasionally.
Remove the lid and simmer for an additional 10 minutes, stirring occasionally, until the sauce has thickened. Taste and adjust the seasonings, as desired.
Serve the slow-braised beef and cherry tomato sauce over cooked pasta or mashed potatoes. Garnish with fresh parsley, if desired.
Interesting Facts
Braising is a cooking method in which food is cooked slowly in a covered pot with a small amount of liquid.
Cherry tomatoes are a small variety of tomato that are sweeter and less acidic than regular tomatoes.
Balsamic vinegar is a type of vinegar made from grapes that has a sweet and tangy flavor.