1. Trim the roots and top 3cm off the leeks. Halve them and rinse out any grit. Finely slice them. Warm 2 tbsp oil in large heavy-based pan or casserole dish for 2 mins, then add the leeks. Season with a good pinch of salt and pepper. Turn the heat to low and sweat for 10 mins, stirring occasionally, till the leeks are soft.
2. While the leeks sweat, halve the squash, scoop out the seeds and peel it. Chop it into dice around 1/2-1cm across (or, if you have a food processor, whizz it through the grater attachment). Peel and grate or crush the garlic. Crumble the stock cubes into a pan or bowl and pour in 2 ltrs boiling water. Stir to dissolve.
3. When the leeks are tender, stir in the squash and garlic. Cover. Sweat for 10 mins to soften the squash.
4. Stir in the risotto rice. Add a ladleful of the stock to the. Cook, stirring a few times, till the stock is absorbed. Repeat till you have used up all the stock and the risotto is creamy and thick. You don't need to stir constantly, just every few minutes.
5. While the risotto cooks, tip the almonds into a dry frying pan. Toast over a medium heat, shaking the pan, till the almonds are golden and smell nutty. Tip into a bowl and set aside. Finely chop the sage leaves.
6. When the risotto is thick and creamy, stir in the sage. Taste and add more salt and pepper if you think it needs it. Ladle the risotto into warm bowls and top with the almonds to serve.
7. TIP: If you want to save the risotto, cool it in portions then chill in the fridge for up to 3 days. Reheat thoroughly before serving.
8. TIP: If you don't to stand and stir, you can make this risotto in the oven. Sweat the leeks, squash and garlic in a pan, following the recipe. Tip them into a casserole dish or large oven dish and stir in the rice and stock. Cover with foil or a lid. Cook in a preheated oven at 180C/Fan 160C/Gas 4 for 45 mins, till the rice is plump and tender.