Warm your oven to 200C/Fan 180C/Gas 6. Peel and thinly slice the onions. Scrub the carrots and cut them on an angle into 1cmm thick slices. Halve the mushrooms. Peel the garlic and thinly slice it. Scatter the onions, carrots and garlic into a large roasting tin. Pour in 2 tbsp olive oil and add a pinch of salt and pepper. Toss to combine, then slide the tin into the oven for 20 mins.

Meanwhile, peel and roughly chop the potatoes so they’re about the same size. Place in a large pan and cover with cold water. Add a pinch of salt and bring to the boil. Simmer for 20 mins till the potatoes are tender when pierced with a knife. Drain and leave to steam dry in the colander for a min or 2. Tip the spuds back into the pan. Add the butter, then pop a lid on the pan to keep potatoes warm.

When the veg has roasted for 20 mins, remove the tin from the oven. Scatter over 2 tbsp flour, 1 tbsp sugar and crumble in the stock cube. Stir to coat the veg. Slowly pour in 500ml boiling water, stirring frequently, till the sauce has thickened and the flour, sugar and stock have dissolved. Add the mushrooms and chicken sausages to the tin and give everything a final stir. Return the tin to the oven for 25-30 mins, till the sauce is sticky and the sausages are cooked through.

Spoon piles of mash into shallow bowls. Scoop the sausages, veg and gravy over the top and serve.