Preheat the oven to 200°C fan (425°F). Pour the cashews and hot vegetable stock into the heat-proof bowl, then leave them to soften while preparing the vegetables.

Cut the cauliflower into florets and cut the peeled sweet potatoes into 2 cm chunks. Thinly slice the onion and garlic.

Add the cauliflower, sweet potatoes, onion, garlic, 2 tablespoons olive oil, salt, and black pepper to the large casserole dish. Toss until the vegetables are evenly coated.

Roast the vegetables for 35–40 minutes. Cook until the cauliflower and sweet potatoes are tender and golden at the edges.

Zest and juice the half lemon. Add the softened cashews and stock to the high-speed blender with oat milk, nutritional yeast, Dijon mustard, lemon zest, lemon juice, salt, and black pepper.

Blend the sauce until completely smooth and creamy. Scrape down the blender sides if needed and blend again.

Drain and rinse the butter beans. Add the butter beans, kale, and blended cashew sauce to the roasted vegetables, then mix until evenly combined.

Drizzle the remaining 1 tablespoon olive oil over the top if desired. Bake for 15–20 minutes until the sauce is bubbling and the top is golden.

Rest the bake for 5 minutes before serving. Divide into 4 portions and serve hot, optionally with steamed greens.