Heat a skillet over high, then coat with olive oil. Add garlic and cook until fragrant. Add chickpeas and red-pepper flakes; cook until chickpeas begin to brown and pop, about 3 minutes. Stir in diced tomatoes and their liquid, 1/4 cup water, and olives and simmer 1 minute; season with salt. Brush bread slices with oil and season. Spoon chickpea mixture on bread and drizzle with oil. You can top this off with tuna or sardines for an extra hit of protein.