Mince the shallot into small 1/8-inch pieces and mash the garlic clove with the side of your knife to release its oils. In a bowl or jar, whisk together the minced shallot, mashed garlic, rice vinegar, lemon juice, honey, and fresh thyme until combined. Slowly drizzle in the olive oil while whisking constantly to emulsify the dressing, creating a smooth, creamy texture. Season with salt and a few grinds of black pepper to taste. I like to let this dressing sit for a few minutes before using it—this allows the garlic and shallot flavors to mellow slightly and blend with the other ingredients.
While the dressing rests, prepare all your salad ingredients. Slice the red onion into thin 1/8-inch half-moons and place them in a small bowl. Slice the pear into 1/4-inch wedges—do this close to serving time to prevent browning. Toast the walnuts in a dry skillet over medium heat for 2-3 minutes, shaking occasionally, until fragrant and lightly golden; this brings out their nutty flavor and adds textural contrast. Crumble the goat cheese and blue cheese into bite-sized pieces and set aside. Having everything prepped and ready makes assembly quick and keeps the greens fresh.
Place the arugula in a large salad bowl or on individual plates. Arrange the sliced red onion, pear wedges, toasted walnuts, and both cheeses over the arugula. Sprinkle the microsprouts on top for a fresh, delicate finish. Drizzle 2-3 tablespoons of the vinaigrette dressing over the salad and gently toss everything together using salad tongs or two forks, being careful not to bruise the delicate arugula leaves. Taste and adjust seasoning with a pinch more salt or black pepper if needed.
Transfer the dressed salad to serving plates or serve family-style from the bowl. Pour the remaining vinaigrette into a small bowl or drizzle bottle and pass it at the table, allowing guests to add more dressing to their preference. The balance of creamy goat cheese, tangy blue cheese, sweet pear, and peppery arugula with the honey-sweetened vinaigrette creates a perfectly harmonious bite—trust the dressing as is, but extra on the side lets everyone customize their own salad.