Shamrock Tea Sandwiches

In a food processor or blender, chop onion and cucumber 3-5 seconds. Scrape sides of processing bowl or blender with a rubber spatula. Process again 3-5 more seconds. Remove vegetables and drain well. Add remaining ingredients to drained cucumber-onion mixture. Stir to blend, chill slightly. Spread on thin sliced wheat and white bread, cut into shamrock shapes with a cookie cutter. This is enough to spread two 16 ounce loaves of bread. Very pretty served on a dark green plate lined with a lace paper doily.