Brush slices of rustic bread with olive oil and sprinkle with salt, toast in oven while clams are cooking.
In a large pot heat oil over medium-high. Add garlic, hot pepper flakes, and oregano and cook until fragrant, 1 minute. Add tomatoes, increase heat to high, and cook until tomatoes burst, about 4 minutes. Add clams and 3/4 cup water, cover, and cook until clams open, stirring once, 8 to 10 minutes. Discard any unopened clams. Drizzle with oil to serve.