Nettles grow like mad this time of year. Now, after many childhood tears, it’s time for revenge.They have a grassy, earthy flavor that goes well in risotto or soup and if you like spinach, sorrel and other greens, you’ll love nettles. They’re also free, although ridiculously I’ve seen them for sale in a few farmers’ markets.I’ve paired it with wild garlic in this pesto recipe; it’s coming to the end of the season now it’s June so I’m trying to cram it into everything I can, flowers and all. Mix the pesto through pasta, preferably trofie or trenette, serve it with seared tuna and a tomato salad or toss it through buttery new potatoes or cauliflower. Here I’m serving it with some fresh prawns and sweet potato fries. It keeps for a couple of weeks in the fridge, just top it up with oil every so often.Wear a pair of rubber gloves when picking nettles (they lose their sting after boiling for one minute) and if you don’t have any in your garden, try and avoid picking them from areas well used by dog walkers or foxes…Makes: A big tubfulPreparation time: 10 minutesCooking time: 10 minutesIngredients150g stinging nettles3 cloves of garlic40g parmesan180ml rapeseed oil1 green chilli100g toasted pine nutsA handful of wild garlic leaves and flowersSalt to seasonRapeseed oil for frying180g raw, shelled tiger prawns per person1/3 of a sweet potato each5cm of cucumber1 tbsp black sesame seeds1 tbsp ground turmeric2 spring onions2 red birdseye chillies, slicedJuice of a limeMethod1. Blanche the nettles in boiling water for one minute, refresh in cold water then pick the leaves and discard the stems.2. Add all the ingredients apart from the oil to a food processor and pulse until roughly chopped.3. With the machine running, pour in the oil in a steady stream until you have a fairly coarse but loose paste. Check the seasoning and add more salt if needed.4. Decant into an airtight jar, pour over some oil and store in the fridge.For the prawns and sweet potato:1. Heat about three centimetres of rapeseed oil in a deep, heavy-bottomed pan to about 180c. For each person use about 1/3 of a sweet potato, skin and all, and cut it very finely lengthways into long matchstick chips. I use a mandoline for this with a julienne blade.2. Fry the potato in the oil and drain on kitchen paper. Season with salt, black sesame seeds and turmeric powder then set aside.3. Toss some shelled, raw tiger prawns (I use about 180g per person because I’m greedy) in rice flour and fry in batches in the oil until cooked and crisp. Drain on kitchen paper then stir through a couple of tablespoons of the pesto and toss well. Set this aside for a minute too.4. Salt the cucumber then squeeze out as much liquid as possible. Mix the cucumber, spring onion and red chilli together and season well.5. Divide the sweet potato between the plates, top with the prawns in pesto and the cucumber mix. Serve immediately with a squeeze of lime juice.