Heat the oven and prepare the beetroot. Preheat the oven to 200°C (180°C fan, gas mark 6). Scrub the beetroot well under running water — you want the skin clean but intact, as it protects the flesh and locks in sweetness. Trim the leafy tops to about 2 cm and leave the root tail alone, because cutting it off lets the juices bleed out during roasting. Pat everything dry with a tea towel.

Season and tray up. Tip the beetroot onto a large baking tray and drizzle with the 2 tbsp olive oil. Sprinkle over the salt and pepper, then rub the oil over each beet with your hands until they gleam. You should hear a faint sizzle the moment they hit the hot tray. Spread them out with plenty of space between each one — if they are touching, they will steam rather than roast.

Roast until a knife slides in cleanly. Roast for 40–45 minutes, turning once at the halfway mark. The beets are ready when the skin looks wrinkled and slightly blistered, and a thin knife slips into the centre with no resistance at all, like going into soft butter. If there is any firmness in the middle, give them another 8 minutes and check again.

Toast the walnuts while the beets cool. Scatter the walnuts on a dry frying pan over medium heat for 4–5 minutes, tossing often. They are done when they smell warm and nutty and you hear a faint crackle as the oils release. Tip them straight onto a plate to cool so they do not scorch in the residual pan heat. This one small step is what separates a good salad from a forgettable one.

Make the dressing. Add the extra virgin olive oil, balsamic vinegar, honey, Dijon mustard, and grated garlic to your small jar. Screw the lid on tightly and shake hard for 15 seconds until the mixture turns glossy and slightly thickened. Taste it — it should be sharp, faintly sweet, and rounded. Add a pinch more salt if it tastes flat.

Peel and slice the beets. Once the beetroot is cool enough to handle, about 15 minutes, rub the skins off with a paper towel or your fingers — they should slide away easily. Cut into wedges about 1 cm thick. Wear an apron if you are attached to your shirt; beetroot juice does not negotiate.

Soften the onion. Put the sliced red onion in a small bowl and cover with cold water for 5 minutes, then drain. This takes the harsh raw bite out of it while keeping the crunch, which means the onion complements the sweet beets instead of fighting them.

Assemble the salad. Spread the spinach across your large salad bowl. Arrange the warm beet wedges over the top — the residual heat will gently wilt the leaves underneath, which is exactly what you want. Scatter over the onion, walnuts, and crumbled goat cheese, then spoon the dressing over everything. Finish with the chopped chives and a final grind of black pepper.

Toss gently and serve. Use your salad servers to fold everything together just two or three times — enough to coat, not enough to bruise. Serve immediately while the beets are still faintly warm against the cool cheese.