Toast the bread lightly in a pan or toaster until golden.
In a bowl, mash the drained white beans with a fork or potato masher until mostly smooth.
Heat olive oil in a small skillet over medium heat. Sauté garlic for 30 seconds until fragrant.
Add diced tomatoes, oregano, salt, and pepper to the skillet. Cook for 2-3 minutes until softened and slightly reduced.
Stir in lemon juice and fresh parsley. Mix thoroughly and remove from heat.
Combine the white beans with the tomato mixture, stirring until well blended.
Spread the bean-tomato mixture evenly over the toasted bread slices.
Garnish with additional parsley and a drizzle of olive oil before serving.