1.Place potato and kumara, in a single layer, in a large steaming basket over a pan of simmering water (don’t let base of steamer touch the water). Cover with a lid or foil; steam 12-15 minutes or until tender. Remove from heat. Drain; transfer to a large bowl. Cool.
2.Meanwhile, whisk sour cream, mayonnaise, gherkins, dill, mustard and juice in a small bowl.
3.Combine potato, kumara, sour cream mixture and egg in a large bowl. Serve sprinkled with almonds.