Rinse the baby spinach (and arugula, if using) thoroughly in cold water. Spin in a salad spinner or pat dry with clean towels until no excess water remains. Place the dry greens into a large salad bowl.

Prepare vegetables and cheese

Halve the cherry tomatoes, thinly slice the cucumber and red onion, slice the avocado just before assembling to prevent browning, and crumble the feta or goat cheese. Add the tomatoes, cucumber, and red onion to the bowl with the greens. Gently nestle avocado slices on top and sprinkle the crumbled cheese and toasted nuts over the salad.

Dressing

Make vinaigrette

In a small bowl or jar, combine the lemon juice, Dijon mustard, honey (or maple syrup), minced garlic, salt, and pepper. Whisk while slowly streaming in the extra-virgin olive oil until the dressing emulsifies and thickens slightly. Taste and adjust seasoning with additional salt, pepper, or lemon juice as needed.

Optional: mellow garlic

If you prefer milder garlic flavor, let the dressing rest for 5–10 minutes before using to allow the garlic to mellow and flavors to marry.

Assemble & Serve

Just before serving, drizzle about half of the dressing over the salad and toss gently with salad tongs or clean hands to coat all ingredients evenly. Add more dressing to taste (reserve any extra dressing in the refrigerator for up to 3 days).

Sprinkle the toasted walnuts or pecans and optional garnish (sesame/hemp seeds or croutons) over the top. Serve immediately so avocado stays fresh and greens remain crisp.

Leftovers: Keep dressing separate and store salad components refrigerated up to 1 day; toss again with dressing just before eating.