In a medium bowl or jar, combine the white wine vinegar, Dijon mustard, honey, minced shallot, minced garlic, lemon juice, salt, and black pepper. Whisk or shake until combined.

Slowly drizzle in the 6 tablespoons of extra-virgin olive oil while whisking continuously (or add to jar and shake vigorously) until the dressing emulsifies and thickens slightly. Taste and adjust seasoning — add an extra 1/4 teaspoon salt or a splash more vinegar or lemon juice if needed. Set aside at room temperature.

Croutons

Preheat oven to 375°F (190°C). Cut sourdough slices into roughly 1/2- to 3/4-inch cubes so they become crisp croutons.

Place the bread cubes on a rimmed baking sheet. Toss with 1.5 tablespoons olive oil, 1/4 teaspoon sea salt, and 1/4 teaspoon freshly ground black pepper until evenly coated.

Spread the cubes in a single layer and bake for 10–12 minutes, tossing once halfway through, until golden brown and crisp. Remove from oven and let cool on the baking sheet; croutons will crisp further as they cool.

Salad Assembly

Thinly slice the red onion. If you prefer milder onion flavor, place the slices in a small bowl of cold water for 5 minutes, then drain well and pat dry.

In a large mixing bowl, place the 6 cups of mixed seasonal baby greens. Add the shaved or thinly sliced red onion.

Add 3/4 of the prepared sourdough croutons to the greens (reserve the remainder for garnish). Drizzle about 3 tablespoons of the Dijon vinaigrette over the greens to start — you can add more to taste. Gently toss the salad using salad tongs or clean hands until the leaves are evenly coated but not soggy.

Taste and adjust: if the salad needs more brightness, add an extra 1/2 to 1 teaspoon lemon juice or a splash of vinegar; if it needs salt, sprinkle a small pinch of salt and toss again.

Plate the salad on individual plates or a shared bowl. Finish by sprinkling the reserved croutons on top and grinding a little extra black pepper over each serving. Serve immediately.