A lighter version of mash which goes well with oily fish or steamed vegetables from Yotam Ottolenghi.
Put the potatoes, thyme, mint, garlic, lemon peel and two teaspoons of salt in a large saucepan. Cover with enough cold water to come 2cm above the potatoes, bring to a boil and leave to simmer gently for 20-25 minutes, until the potatoes are soft enough to mash.
While the potatoes are cooking, make the topping. Put the oil, garlic, thyme, mint, lemon zest and juice in a small bowl with an eighth of a teaspoon of salt and a good grind of pepper, and stir to combine.
Drain the cooked potatoes into a sieve set over a large bowl (you’ll need some of the cooking water later, so don’t throw it all away). Pick out the thyme and mint, then return the potatoes to the pan with the garlic and lemon peel.
Using a masher, mash the potatoes; as you go, slowly add 100ml oil and 120ml of the aromatic cooking water, until you have a smooth mash.
Transfer the mash to a platter and use the back of a spoon to make little dips all over the surface. Drizzle the herb and garlic oil evenly over the top and finish with a good grind of black pepper.