1. To make the crackers, mix the thyme with the grated Parmesan. Preheat the oven to 170C/325F/gas 3. Line a baking tray with parchment. Make 5 or 6 mounds of the parmesan mix on the parchment, well-spaced apart, and press them down gently to flatten. Bake for 8-10 minutes until crisp and golden. Cool the crackers on the parchment until set, then remove onto paper towels to drain the grease.
2. Wash the asparagus and break off the woody ends; don’t bin them. Chop the spears except the tips; put those aside. Make up the stock or heat up already made in a pan until boiling. Add the woody ends of the asparagus and let the stock simmer gently next to your risotto pan – that’s to get the maximum flavour from the asparagus.
3. Melt the butter with the oil in a large pan, add the onion and garlic and sweat gently until slightly translucent, over medium heat. Add the rice and start stirring: if you don’t have the girariso – the special wooden risotto spoon with a hole in the middle – and you have a dough whisk, use that. Otherwise an ordinary wooden spoon is fine.
4. When the rise starts hissing (about 3 minutes) and it’s hot, add the wine. Simmer stirring until it’s absorbed. Now start adding the stock, by a ladleful, stirring the rice in between additions. Only add the next ladle when the previous one has been absorbed but don’t let the rice get too dry.
5. After 20 minutes (and about two thirds of the stock) the rice should swell considerably. Add the chopped asparagus stems and keep stirring. After another 5 minutes and a couple more ladles of stock taste the rice – you might not need all the stock. The rice should be almost tender enough to eat but with quite a bite.
6. Take it off the heat, add the 50g of butter and the Parmesan and beat in well – it will look like it’s turning sloppy but don’t worry, it will keep good texture. Stir in half the lemon zest, half the dill and taste for seasoning; it will certainly need some black pepper. The saltiness depends on how salty your stock was. Add the asparagus tips to the pan, cover with a lid and let it rest for a few minutes.
7. Spoon the risotto into the serving plates or bowls, sprinkle with extra zest and dill and serve with the Parmesan crackers on the side.