Peel garlic and chop coarsely. Sprinkle with ¼ teaspoon salt and mash into puree with blade of knife held sideways. Scrape into medium bowl
Remove ends from cucumber and peel. Cut in half lengthwise; scrape out and discard seeds. Coarsely grate cucumber flesh or mince finely with knife
Squeeze grated or chopped cucumber firmly over another bowl or sink to extract as much liquid as possible; discard liquid and add squeezed cucumber flesh to bowl with garlic
Add yogurt, lemon juice, olive oil, dill and pepper, stirring together well
Cover and refrigerate for at least 2 hours to allow flavors to blend. Add more salt if needed
Serve as dip with pita bread or fresh vegetables, or as a sauce for grilled lamb, chicken, beef or vegetables