Cut off any discolouration or the eyes of the potatoes and give them a good scrub. Leave the rest of the skin on.
Add potatoes to a pot and cover with cold water. Stir in a teaspoon of salt and bring to a boil, then lower the heat to a gentle bubble and cook for about 20-30 minutes (depending on the size of the potatoes). Don't worry if the skin cracks as we'll be destroying them anyway.
Strain the potatoes and let them cool for 10-15 minutes. This is important! That beneficial resistance starch will develop further while potatoes are cooling down. In the meantime, preheat the oven to 180-190 C / 370-375 F, depending on how hot your oven gets.
Place a piece of parchment paper on a large, flat tray (or two trays if making a big batch). Add whole potatoes leaving a bit of space between them. Using a potato masher or the bottom of a jar or a bottle, press down on each potato to smash them into a pancake. The flatter they smash, the crispier they will be. But don't go crazy as you want to keep them in a round shape, more or less.
Drizzle generously with olive oil (this will ensure extra crispiness and keep them moist) and sprinkle with plenty of salt and some pepper.
Pop in the oven, middle shelf for 45-50 minutes. You can check on them after 30 minutes to see if you need to rotate the tray or move some of the potatoes around for more even browning.
Once done, top with the salsa verde peas and serve with some fresh herbs on the side (if you wish, for presentation).
Make salsa verde peas. Prepare the ingredients for the salsa verde and add the peas to a pot of boiling hot water for 2-3 minutes. We want them to defrost in hot water and cook very briefly to retain as much of that beautiful green colour as possible. Drain, leave in cold water to cool and strain through a sieve.
Using a mortar and pestle, food processor or your mad knife skills, chop and mince garlic, herbs and capers into a pesto/salsa consistency and combine with lemon juice, olive oil and a touch of salt.
Using a masher, give those peas a smashing workout. You want to break them up a bit but without turning them into a paste or a smooth mash.
Combine the peas with the salsa verde and taste for seasoning and lemon. You can add more salt or acidity depending on how tangy you like them.