This is a light tasting potato salad, though the bacon and potato will still satisfy hearty appetites. You can make this ahead and refrigerate it (in fact, the flavours are better made a day or half a day ahead) but as it's meant to be served warm, bring it back to room temperature before serving.
Wash the potatoes; don't peel or cut them. Set aside. When one pot of water is boiling, put them in it and cook until tender, somewhere between 10 and 15 minutes.
Top, tail and wash the green beans, and cut them up into 2 or 3 inch pieces (5 to 8 cm) [Ed: or just use frozen]; set aside. When their water is boiling, cook them until just tender to the bite, about 7ish minutes. (Or microwave in a bit of water.)
Put the oil into a large mixing bowl. Squeeze in half a lemon (watching out for pits going in.) Chop up the green onion, toss it in, and stir, with a few sprinkles of salt and pepper.
Meanwhile, grill, broil, fry or microwave the bacon until it's crisp, then break it up coarsely into the oil mixture, reserving a handful for garnishing later. Add the drained green beans, stir.
When the potatoes are cooked, drain them. Any that are overly large for a salad, cut them up, but don't peel.
Add the potatoes to bacon and bean mixture. Toss the salad lightly so that you don't break up the potatoes, taste, season more as you think needed with salt and pepper and toss lightly again, then garnish with the reserved bacon and send to the table.
Notes
Instead of new potatoes, you can use salad potatoes. Or larger waxy potatoes, and just cut them up more.For the bacon, use American-style bacon (aka streaky bacon in the UK), or pancetta.For the green beans, you can use frozen or fresh. You can also use runner beans.This recipe is easily doubled or tripled.