Wash the head of butter lettuce under cold running water for about 1 minute. Gently rub the leaves to remove any dirt or debris. Pat the lettuce dry with a paper towel or use a salad spinner to eliminate excess moisture.

Slice the cherry tomatoes in half and slice the cucumber into rounds. Thinly slice the red onion and set aside.

Tear the butter lettuce into bite-sized pieces and place them into a large salad bowl.

Add the halved cherry tomatoes, sliced cucumber, and thinly sliced red onion into the bowl with the butter lettuce.

Sprinkle crumbled feta cheese and chopped walnuts or pecans over the top if using.

Drizzle olive oil over your salad, followed by balsamic vinegar or lemon juice. Season with salt and pepper to taste.

Gently toss all the ingredients together using salad tongs or clean hands to coat everything with the dressing.

Serve immediately on individual plates or from the salad bowl.