Preheat your oven to 200°C/Fan 180°C/Gas 6. Trim the stalk from the onion squash and slice the squash in half. Scoop out the seeds with a spoon and slice into thin wedges (no need to peel). Pop in a roasting tin. Drizzle over 1 tbsp olive oil and sprinkle with a little salt and pepper. Toss to coat the wedges in the seasoned oil. Set aside.
Peel the red onions and cut them into 8 wedges each. Slice the tomatoes into wedges of a similar size to the onions. Drain and rinse the chickpeas, then shake dry. Arrange the tomatoes, onions and chickpeas in a second roasting tin and toss them with 1 tbsp oil and a little salt and pepper.
Slide both roasting tins into the oven for 25 mins, till the veg are tender and caramelised.
Meanwhile, warm a pan over a medium-high heat for 1 min. Scatter the pine nuts into the dry pan and toast for 2-3 mins, stirring frequently, till golden brown on all sides. Tip into a bowl.
Roughly chop the kale leaves and tuck them into a food processor. Add most of the toasted pine nuts (save a pinch for later). Peel and grate in the garlic, and grate in the lemon zest. Squeeze in the lemon juice, and pour in 1 tbsp oil. Spoon in 2 tbsp cold water. Add a pinch of salt and pepper and whizz till everything comes together into a pesto. Add a splash more water if it seems too dry.
Add the roast veg and chickpeas to the squash with the salad leaves and half the kale pesto. Arrange on a couple of plates and finish with the remaining pesto and the reserved pine nuts.