Add olive oil, lemon juice, salt, and pepper to a small jar with lid. Shake until well combined.
Taste, then adjust seasoning with additonal salt and pepper, if needed. Set aside.
Assemble Salad:
Tear or chop lettuce into bite size pieces, then add to a large bowl. Top with cucumber, tomatoes, and red onion.
Drizzle salad lightly with dressing, then toss gently. Add more dressing while mixing, if needed, using just enough to lightly coat greens and veggies (you may have leftovers).
Taste salad, then add a pinch of salt and pepper, if needed.
Serve salad immediately, topped with croutons. Enjoy!
Notes
Lettuce - I used one large head of green leaf lettuce, which yielded about 10 cups of torn greens. Substitute romaine, mixed greens, red leaf lettuce, iceberg, butter lettuce, or any combination of greens that you like. You'll need about 10 to 12 cups (recipe is flexible).Veggies - Feel free to clean out the fridge or swap in your favorite veggies! You'll find lots of ideas before this recipe card. Tip: For less bite, rinse the onion under cold water after slicing, then blot dry.Dressing - I love this simple Lemon Dressing used here, but almost anything goes. My Maple Vinaigrette would also be delish, as would an Italian vinaigrette, blue cheese dressing, ranch, thousand island, etc.More Tips - Don't forget to read the info before this recipe for helpful tips and tons of topping ideas!