1.      Preheat oven to 300 F. Horizontally trim 1/2 inch or so off the top of the garlic bulb. Set garlic, cut-side-up, in a small baking dish. Drizzle garlic with 2 tsp olive oil. Cover with foil and roast 60 to 70 minutes, or until garlic is very tender. Cool garlic to room temperature.

2.      When garlic has cooled, squeeze the flesh out of each clove on to a cutting board; discard the skins. Finely chop the roasted garlic and set in a bowl. Mix in the mayonnaise, juice, mustard, Worcestershire, cheese and parsley (or green onion). Taste aioli and season with salt and pepper, as needed. The aioli can be made many hours in advance. Cover and refrigerate until needed

3.      To cook steaks, heat your barbecue or indoor grill to medium-high (see Options). Pat steaks dry with paper towel. Brush steaks lightly with 1 tbsp olive oil; season steaks with salt and pepper. Grill steaks to the desired doneness, allowing about 2 to 3 minutes per side for rare, and 3 to 4 minutes per side for medium-rare to medium. Plate steaks and serve with the aioli.