Heat a grill pan, or cast-iron or heavy non-stick frying pan.
In a small dish that can take the steak snugly later, combine the extra-virgin olive oil, red pepper flakes, dried oregano, salt, and red wine vinegar. Oil the steak lightly and put it in the hot pan and cook for 2 minutes on each side, then remove it to the dish of spicy marinade and sit the cooked steak for 2 minutes a side in the dish. Your steak will be rare, but that's the way it's meant to be.
Remove the steeped steak to a board, ready for slicing, and while it sits there, arrange the cherry tomatoes, cut-side down, in the marinade dish. Cut the steak into thin slices on the diagonal and arrange on a serving dish or 2 dinner plates.
Smoosh the tomatoes around in the marinade, then pour them, and the marinade, over the ribbons of meat. Add a few leaves of fresh oregano, if you can get them, and serve immediately.