Boil the potatoes with a little salt until done. Let them cool down and then peel and dice them approximately to the same size. Set aside.
Finely chop the onions. Core and peel the apples and diced them too with the pears to the same size as the potatoes. Drain the canned pineapples and chop them into small pieces. You can discard the canned pineapple sugar syrup or use it in any other recipes.
In a big bowl, combine the onions, apples, pears, pineapples, sweetcorn and season well with salt and pepper. Drizzle olive oil and lemon juice too.
Now toss in the potatoes and mix in the freshly chopped coriander leaves too.
Refrigerate and serve chilled.