But your tuna salad will need more than just some mayo to become a flavor-fest, and that's where balsamic vinegar comes in! This rich, syrupy condiment adds a complex sweetness that perfectly ...

1. In a sturdy re-sealable plastic bag, combine the vinegar with 1/2 cup of the olive oil and the rosemary. Add the steak, seal the bag and refrigerate overnight, turning the bag several times.