Substitute 1/4 cup freshly chopped basil for the oregano. Instead of using pita triangles, brush thick slices of good-quality rustic bread with some olive oil and grill until browned. Rub the grilled bread with a clove of garlic and serve with the salad.
1. Prepare a charcoal or gas grill until hot, placing rack 3 or 4 inches from the heat source. Meanwhile, thread tomatoes and shrimp on separate skewers. Brush with about 2 Tbs. oil. Grill, turning once, for about 5 minutes. The tomatoes are done when just charred; the shrimp should be opaque.
2. As skewers cook, brush the bread with a bit of oil and put them on the grill for about 30 seconds on each side.
3. Put the lettuce in a serving bowl and toss with 1/4 cup oil, the lemon juice, and salt and pepper to taste. Add olives and basil, and toss again. To serve, divide the salad among 4 plates, topping each with shrimp, tomatoes, and cheese. Rub the grilled bread with a clove of garlic and serve with the salad. Garnish with the grilled bread slices.