• Preheat the oven to 220°C/200°C fan/gas mark 7. Dilute the stock in 750ml hot water (double for 4p). 
• Halve, peel and chop the onion into small pieces. Thinly slice mushrooms.
• Remove the root and the dark green leafy part from the leek then cut in half widthways. Take half (double for 4p) and halve lengthways, then thinly slice.
• Peel and grate the garlic (or use a garlic press).
• Roughly chop walnuts. Roughly chop spinach.

• Place a large pan over medium heat with 3 tbsp butter (double for 4p).
• When hot, add onion, leek and mushrooms. Season with salt.
• Cook until softened, stirring occasionally, 2-3 mins.
• Add the garlic and vinegar.
• Cook, stirring constantly, until fragrant, 1-2 mins.

• Add the rice, stir and cook until edges of rice are translucent, 1-2 mins.
• Stir in a ladle of your stock. When stock has been absorbed, stir in another ladle.
• Keep the pan on medium heat and continue stirring in stock, letting it absorb each time. Cooking time should take 25-30 mins and your risotto is done when the rice is al dente—cooked through but with a tiny bit of firmness left in the middle.
• Add additional water if it becomes too dry.

• Meanwhile, add tomatoes and 1 tbsp oil (double for 4p) to a lined baking tray. 
• Season with salt and pepper, then toss to coat.
• Roast in the middle of the oven until tomatoes start to burst, 10-11 mins. 

TIP: Keep your eye on them so they don't burn!

• When the last of the stock has been absorbed and rice is creamy, add cheese and spinach to risotto.
• Stir until spinach wilts, 3-4 mins.
• Stir in roasted tomatoes.
• Season to taste with salt and pepper.

• Divide risotto between bowls.
• Finish with a sprinkling of walnuts.