Preheat your oven to 200°C/Fan 180°C/Gas 6. Scrub the potatoes and halve or quarter them so they're all roughly the same size. Pop them in a large roasting tin and drizzle over 1 tbsp olive oil. Season with salt and pepper and toss to coat, then slide the tin into the oven for 15 mins.

While the potatoes roast, trim and peel the red onion and slice into around 8 wedges. Pop them into a large bowl. Halve the red pepper, scoop out the seeds and pith and roughly chop the pepper. Add it to the bowl. Trim the courgette and slice it into 1cm-thick rounds. Add them to the bowl.

Peel and finely chop the garlic. Finely grate the zest from the lemon, then slice the lemon into 4 wedges. Finely chop the parsley stalks, setting the leaves aside for later. Add the garlic, lemon zest and parsley stalks to the bowl with a pinch or 2 of harissa (it's hot, so use as much or as little as you prefer) and 1/2 tbsp olive oil. Season with salt and pepper and toss to mix.

When the potatoes have roasted for 15 mins, take them out of the oven. Add the veg to the tin and toss to mix everything together, spreading it out into an even layer. Add the tofu grill herb sausages to the tin. Drop in the lemon wedges. Snip the cherry vine tomatoes into 2 bunches and add them to the tin. Slide the tin back into the oven and roast for 25-30 mins till the sausages are browned and the veg are lightly charred.

Roughly chop the parsley leaves. Serve the roast veg and sausages on warm plates, with the roast lemon wedges on the side for squeezing, garnished with the parsley leaves.