Whisk together all of the ingredients (Greek yogurt, milk, honey, dijon, and poppy seeds) together in a small bowl. Store in an airtight container in the fridge until ready to use.: The moment you whisk, you will notice the dressing transform from separate components into a smooth, glossy emulsion, with tiny black flecks from the poppy seeds that look appealing against the pale dressing. Focus on achieving a slightly silky consistency so it coats the back of a spoon, this indicates the right milk to yogurt ratio. If the dressing seems too thick, add small splashes of milk until it loosens, stirring steadily to avoid lumps. A common mistake is over sweetening the dressing; taste as you go so the honey complements but does not dominate. Whisking briskly also helps release the aroma from the Dijon mustard , brightening the whole mixture and ensuring each leaf gets flavor when tossed.
Add the spinach, strawberries, walnuts, raspberries, blueberries, and goat cheese to a large bowl. Drizzle over as much dressing as you like (I usually use about 1/2-3/4 of it) and toss to combine.: You will feel reassured knowing the dressing stays fresh and chilled, the coolness preserving the tangy notes from the yogurt . Place the dressing in a sealed jar to prevent fridge odors from altering the flavor, and give it a quick stir before using because the poppy seeds may settle. Many home cooks make the error of leaving it uncovered which dulls the brightness, so airtight is essential. The fridge also firms the dressing slightly, making it easier to portion, and storing ahead lets the flavors meld for a more cohesive taste when you drizzle it over the salad.
Serve immediately.: When you combine these components, you will notice a colorful contrast and varied textures, from the soft baby spinach leaves to the jewel like blueberries . Toss gently with your hands or salad tongs so the delicate raspberries do not rupture, and distribute the crumbled goat cheese so each portion gets creamy pockets. One pitfall here is over mixing which bruises the berries and wilts the leaves; instead, fold the ingredients together with a light touch. The scent should be fresh and fruity, and the visual should be vibrant with green leaves dotted by red and blue berries and specks of white cheese.
Drizzle over as much dressing as you like (I usually use about 1/2-3/4 of it) and toss to combine: As you pour the dressing, notice how it beads and then spreads across the leaves, clinging to the spinach and pooling in little crevices of the berries. Start with a modest amount, then toss and taste, adding more if you want a creamier mouthfeel. The right amount will lightly coat rather than saturate the leaves, preserving the crispness; overdressing leads to limp spinach and a muddled flavor. Listen for a soft rustle as you toss, and aim for an even, glossy coating that makes the salad look appetizing and balanced.
Serve immediately: This is the moment the salad delivers its best texture, with crisp spinach and intact berries that pop pleasantly when bitten. If you wait, the leaves will soften and the berries may release juice, altering the intended balance. Plate straight away on chilled bowls for a refreshing contrast, and add a final few crumbles of goat cheese or a handful of extra walnuts for presentation if desired. A common oversight is prepping the salad too far ahead while dressed, so serve right away to maintain that bright, fresh experience that makes this dish special.
