Preheat grill to medium-high heat.
Drizzle the bread with the olive oil and place onto preheated grill. Grill until golden brown, about 2 to 3 minutes per side.
In a medium bowl, combine ricotta, tomatoes, olives, basil, and salt and pepper.
Squeeze lemon over the bread. Sprinkle bread with oregano and salt and pepper, to taste.
Place ricotta mixture on top of the grilled bread, garnish with basil leaves and serve.
Recipe courtesy of Giada DeLaurentiis, 2007