1. Preheat your oven to 180°C/Fan 160°C/Gas 4. Scrub the potatoes and chop them into 2-3cm-thick chunks. Trim and chop the carrots into 2cm-thick slices. Peel and thickly slice the onions. Tumble the veg into a large roasting tin. Toss with 2 tbsp oil and some salt. Roast the oven for 30 mins.
2. While the veg roast, squeeze ½-1 tbsp massaman curry paste into a medium bowl (use more or less, depending on how spicy you’d like the curry). Add a good pinch of salt. Crumble in the beef mince, then mix it with the massaman paste, making sure everything is combined.
3. Shake the tin of coconut milk and pour it into a bowl. Whisk in 1 tbsp fischy sauce. Finely grate in the zest from both limes and squeeze in the juice from 1. Add a pinch of salt and mix together.
4. When the veg have cooked for 30 mins, remove the tin from the oven and turn the veg over a few times. Crumble the spiced beef mince over the veg. It doesn’t matter if the pieces are different sizes, as that will add to the texture of the finished dish.
5. Pour in the coconut milk mixture, pushing some of the beef pieces into the coconut sauce. Slide the tin back into the oven for 20 mins.
6. While the massaman curry cooks, cook the rice. Fill and boil your kettle. Rinse the rice under cold water and tip it into a large pan. Add 600ml boiling water and a pinch of salt. Cover, bring to the boil, then turn the heat right down. Cook for 8 mins, till all the water is absorbed and the rice is tender. Take the pan off the heat and let it sit, lid on, for 5-10 mins to finish cooking the rice.
7. Finely slice the chilli (you can scrape out the seeds and white pith for less heat, or leave it out altogether). Roughly chop the coriander leaves and stalks. Cut the remaining zested lime into quarters. Roughly chop the peanuts.
8. Remove the tin from the oven. The potatoes should be soft and slightly crisp. The beef mince should be lightly browned. Scatter over the chilli (if you’re using it), coriander and chopped peanuts. Serve with the fluffy rice and wedges of lime.