IN A LARGE MIXING BOWL, toss together the orzo, peas, olives, peppers, shrimp, onion and parsley. Pour the olive oil over the salad and mix well.
Add the vinegar, garlic, salt and pepper and taste to adjust the seasonings, adding more vinegar or oil sparingly as needed. Don't make the salad too moist. Spoon the mixture into a mixing bowl just large enough to hold the salad, packing it down slightly, cover and chill thoroughly.
Unmold the salad onto a serving platter and garnish with cherry tomatoes and black olives. Split the reserved shrimp in half lengthwise and place them on the top for decoration.