Make the dressing: place the garlic in a small dish, salt it, and pour the lemon on top. Let stand at least 20 minutes and up to 4 hours.
Place the cubed cucumbers and tomatoes in a colander and lightly salt. Let stand 20 minutes, then shake out any accumulated water.
If you don’t want raw garlic in the salad, strain the lemon juice into the salad bowl (or, if you choose, add with raw garlic still in it). Add the olive oil, and whisk together. Add in order olives, onions, feta, cucumber tomato mixture, and greens. Toss well. Serve with bread or spanikopita if desired.