Heat the oven to 200C/Fan 190C/ Gas 8. Peel the butternut squash. Cut it into 2cm chunks, discarding the seeds. Tumble it on to a baking tray. Drizzle with 1 tbsp olive oil and scatter over some salt and pepper. Roast for 30 mins till the squash is tender and charring on the edges.
While the squash roasts, tip the buckwheat into a pan. Cover with boiling water and simmer for 15-20 mins till the buckwheat is soft. Drain and rinse under cold water.
While the squash and the buckwheat are cooking, prepare your kale. Pull the leaves from the stalks. Finely chop the stalks. Slice the kale into large pieces. Peel and finely grate the garlic clove.
Whisk the tahini and 1 tbsp tamari with the garlic and ½ tbsp oil in a large bowl. Add the kale leaves and stalks and massage the tahini dressing into the leaves. Set to one side.
Halve the chill and flick out most of the seeds. Finely chop it. Whisk with 2 tbsp cider vinegar and 2 tbsp honey.
After the squash has cooked for 30 mins, remove from the oven. Pour half the cider and chilli dressing into the buckwheat and stir to coat. Pour the rest over the squash. Tip the buckwheat onto the tray with the squash. Spread everything out. Scatter over the pumpkin seeds. Slide back into the oven for 10 mins.
Lay the tahini massaged kale onto a separate baking tray. Scatter over the sesame seeds and cumin seeds. Place in the oven on a shelf above the squash for 5 mins. The kale should soften and the edges darken in colour and turn crisp.
Taste the buckwheat and squash, seasoning if necessary. Spoon into warm bowls. Pour over the remaining chilli dressing. Top with the sesame roasted kale. Add more tamari to taste.