Place steak in a re-sealable plastic bag.
In a separate bowl, mix 1/2 cup red wine, 1/4 cup olive oil, 4 chopped garlic cloves, 1 tbsp fresh thyme, and lots of fresh black pepper.
Pour marinade onto steak and turn to coat. Seal bag and refrigerate for at least 6 hours (flipping after 3 hours).
Remove from fridge and fire up the grill.