Prepare the walnuts: Place a small dry frying pan over medium heat. Add the chopped walnuts and toast for 3-4 minutes, stirring frequently. You'll know they're ready when the kitchen fills with a warm, nutty aroma and the walnuts turn a shade darker with golden-brown edges. Tip them onto a plate to cool — they'll become crisp as they sit.

Make the dressing: In a small jar with a tight-fitting lid, combine the olive oil, balsamic vinegar, Dijon mustard, honey, and a pinch of salt and pepper. Screw the lid on firmly and shake vigorously for about 20 seconds until the dressing looks thick and emulsified — it should have a uniform, slightly creamy appearance with no visible separation.

Prepare the beets: If using pre-cooked beetroots, drain them and pat dry with kitchen paper. Cut them into 2cm cubes — the pieces should be bite-sized with a deep, jewel-like magenta colour. If they feel slippery, blot them again to ensure the dressing clings properly later.

Slice the red onion: Peel the onion and cut it in half through the root. Slice each half thinly into half-moons — aim for pieces about 3mm thick. They should look translucent and will soften slightly once they meet the dressing, losing their raw bite.

Assemble the salad: Place the baby spinach in a large salad bowl. Add the diced beets, sliced red onion, and cooled walnuts. Toss gently with your hands or salad servers until everything is evenly distributed — the bright green spinach should be flecked with deep red beets and golden walnuts.

Add the dressing and cheese: Drizzle about three-quarters of the dressing over the salad and toss again gently. Add the crumbled goat cheese, crumbling it with your fingers into small, uneven pieces that look like soft white pebbles scattered through the bowl. Drizzle the remaining dressing over the top and give one final gentle toss.

Finish and serve: Sprinkle fresh thyme leaves over the top if using, and add a final crack of black pepper. The salad should look vibrant and glossy, with the cheese starting to soften slightly against the warm beets. Serve immediately while the spinach is still crisp and the walnuts retain their crunch.