Preheat the oven to 200°C/Fan 180°C/Gas 6. Scrub the sweet potatoes. Cut each into 6-8 wedges. Place them in a bowl and pour in 1 tbsp olive oil. Scatter in 2 tsp harissa and some seasoning. Toss together to coat in the oil and spice mix.
Tumble the potatoes onto a lined baking tray. Slide into the oven and roast for 20 mins.
Peel and thickly slice the onion. Cut any large tomatoes in half. After the potatoes have roasted for 20 mins, remove the tray from the oven. Add the onion and tomatoes. Using a spoon, toss everything together. Slide back into the oven for 20 mins.
While the veg is roasting, zest and juice the lemon. Stir the zest into the pot of ricotta with a generous crack of pepper and pinch of salt. Mix well.
Whisk the lemon juice with 1 tbsp honey and ½ tbsp oil to make a creamy dressing. Chop the half-cucumber into small chunks. Add to a bowl with the salad mix.
Remove the veg from the oven. It should all be cooked and lightly charred. Drizzle over 1 tbsp honey. Scatter over the pumpkin seeds. Slide back into the oven for 5 mins.
Toss the cucumber and salad leaves with the lemon dressing. Spoon the roasted veg onto warm plates. Dot over the lemon ricotta. Snip over the chives with a pair of scissors. Serve with the lemon dressed salad.