Preheat the oven to 200˚C, gas mark 6. Toss together the potatoes, oil and garlic cloves and arrange on a non-stick baking tray. Roast for 25 minutes, stirring halfway, until tender.
Meanwhile, lower the eggs into a large saucepan of simmering water and cook for 7 minutes, adding the beans for the final 2 minutes. Drain everything in the pan and rinse under cool water. Peel and quarter the eggs.
Remove and discard the skin from the cooked garlic cloves, trim, then mash in a bowl. Stir in the yogurt, mayonnaise, Worcestershire sauce and cheese.
Season and add 1 tbsp warm water from the kettle to loosen. Arrange the lettuce, potatoes, eggs and beans on plates and spoon over the dressing, adding extra shavings of the cheese and a grinding of black pepper to serve.