Wash and thoroughly dry the mixed salad greens using a salad spinner or clean kitchen towels. Halve the cherry tomatoes, thinly slice the cucumber and red bell pepper, very thinly slice the red onion, julienne or shred the carrot, and dice the avocado if using. Place all prepared vegetables in a large salad bowl.

Add cheese and nuts

If using, crumble the feta or goat cheese over the greens. Sprinkle the toasted nuts or seeds evenly across the salad. Keep the avocado aside to add just before serving if you want it to stay firm and not brown.

Simple Vinaigrette

In a small bowl or jar with a tight lid, combine the lemon juice or vinegar, Dijon mustard, honey or maple syrup, and minced garlic. Add the salt and pepper. Whisk or shake briskly while slowly pouring in the olive oil until the dressing is emulsified and slightly thickened. Taste and adjust seasoning—add a pinch more salt or a little more honey if desired.

Dress and toss

Drizzle about two-thirds of the vinaigrette over the salad (reserve the rest for guests to add more if desired). Using salad hands or tongs, gently toss the salad until the ingredients are evenly coated. Add the diced avocado and gently fold it in. Taste and add more dressing, salt, or pepper if needed.

Transfer the tossed salad to a serving bowl or plates and serve immediately so greens stay crisp. Pass remaining dressing at the table.