Crumble cheese; place ½ cup in a small mixing bowl and set remainder aside. Add garlic, yogurt, and red wine vinegar to bowl; combine and set aside while you cook the steak.

Trim steak and cut into 2-inch pieces. Pat dry and season with salt and pepper. Heat reserved bacon fat in a skillet over medium-high heat until just smoking. Add steak and cook until well browned on all sides and meat registers 125ºF for medium-rare, about 7 minutes. Transfer to a plate, cover, and let rest.

While the steak rests, taste dressing and add salt and pepper as desired. Cut lettuce into 8 wedges and remove cores. Halve or quarter tomatoes, and thinly slice chives or green onions. Arrange 2 lettuce wedges each on 4 serving plates. Divide steak tips among plates. Top steak and lettuce with tomatoes, bacon, and remaining crumbled sheet. Sprinkle with chives or green onions; pass salt and pepper at the table.