Place baby arugula in a salad spinner or large bowl, rinse under cold water, and gently spin or pat dry with clean kitchen towels or paper towels. Thoroughly dry so dressing clings and leaves don't wilt.

Prepare vegetables and toppings

Halve cherry tomatoes, thinly slice cucumber and red onion, shave Parmesan with a vegetable peeler if not pre-shaved, and measure toasted pine nuts. If using avocado or chicken, prepare and have ready.

Dressing

In a small bowl or jar combine lemon juice, Dijon mustard, honey (or maple), salt, and black pepper. Whisk together while slowly streaming in the olive oil until the dressing emulsifies into a glossy vinaigrette. Taste and adjust seasoning — add a pinch more salt or a squeeze of lemon if needed.

Toasting nuts (if not pre-toasted)

Warm a small dry skillet over medium heat. Add pine nuts or chopped walnuts and toast, stirring frequently, until fragrant and lightly golden, about 2–4 minutes. Remove immediately to a plate to cool so they don't continue to brown.

Assemble

Place the dried baby arugula in a large salad bowl. Add the halved cherry tomatoes, sliced cucumber, and thinly sliced red onion. Drizzle about two-thirds of the vinaigrette over the salad (you can reserve the rest for guests to add more). Toss gently but thoroughly so all leaves are lightly coated.

Scatter shaved Parmesan and toasted pine nuts over the tossed salad. If using optional add-ins (grilled chicken, avocado, or croutons), arrange them on top. Grind an extra turn of black pepper over the salad and taste; add more dressing or a pinch more salt if desired.

Serve immediately on chilled plates to keep the arugula crisp. Leftover dressing can be stored in the refrigerator for up to 5 days.