Start by washing the baby spinach. Remove any wilted leaves. Then, dry the spinach using a salad spinner or pat it dry. Next, thinly slice the leeks, making sure they're clean and free of grit. Set both ingredients aside.

In a mixing bowl, combine the red or white miso paste, dried miso flakes, extra virgin olive oil, truffle oil, yuzu juice, and lemon zest. Whisk them together until you achieve a smooth consistency. This dressing should be creamy but loose enough to coat the spinach easily.

In a large bowl, add the spinach and leeks. Drizzle the dressing over the top. With clean hands or tongs, gently toss the ingredients together. Be careful not to crush the spinach. You want it to remain light and airy.

Once the salad is dressed, sprinkle the finely grated Parmesan cheese over the top. Add a dash of freshly cracked black pepper and the toasted sesame seeds. This final layer adds texture and flavor, making your salad visually appealing.

Transfer the salad to a serving dish or individual bowls. You can garnish it with a bit more Parmesan or sesame seeds if desired. Serve immediately, or let it chill for a bit to blend the flavors. Either way, your guests will be impressed.