Peel and chop the potatoes into bite-sized cubes.
Boil the potatoes in salted water until tender, about 15-20 minutes.
Drain the potatoes and let them cool completely.
Dice the cucumber and chop the onion.
In a large bowl, combine the cooled potatoes, cucumber, peas, corn, and onion.
In a separate bowl, mix the mayonnaise, olive oil, lemon juice, salt, and pepper.
Pour the dressing over the potato mixture and gently toss to combine.
Add the chopped dill and mix again.
Taste and adjust seasoning if necessary.
Chill the salad in the refrigerator for at least 30 minutes before serving.