Beef with vinegar

2 tablespoons olive oil 1 1/2 lbs beef stew meat 10 cups water 4 large carrots , peeled and diced 4 stalks celery , diced 1 onion , chopped 2 cups frozen[...]

4 medium red potatoes, each cut into 8 wedges 1/4 cup water 1/2 red onion , thinly sliced 1 lb roast beef 1 pint grape tomatoes , cut in half lengthwise 9[...]