Roast garlic for about 5 minutes at 400 degrees F. A toaster oven is ideal for this.
Partially peel cucumber, leaving strips of green along length. Cut cucumber in half lengthwise, and then into 1/2-inch slices. Cut tomatoes into wedges.
Finely mince roasted garlic, and combine with oil, lime juice, salt, and pepper flakes. Toss with cucumber and tomato.