1. Halve the potatoes and boil them in salted water until tender and cooked through; drain. Beat the mayonnaise, yoghurt, garlic and lemon juice together and season to taste with salt and pepper. Mix through the potatoes while hot and spoon onto a plate. Sprinkle the radishes on top.
2. Season the pork strips with salt and pepper to taste. Heat the oil in a heavy-bottomed pan over high heat; add half of the pork. Work in batches so that there is plenty of space around each strip in the pan. Let the strips brown on one side, turn over with tongs or a spatula and then fry on the other side. Remove and repeat with the rest.
3. Stir-fry the garlic and ginger together in the same pan until fragrant. Stir in the sauce and mix until heated through and bubbling. Spoon the fried pork back into the sauce and mix until coated and glazed. Serve with the potato salad and a green salad.