Yeah, yeah, the classic ratio of oil and vinegar in dressing is one part vinegar/acid to three parts oil. I do equal parts oil and lemon juice. Truth is, if I was ever to open a restaurant it would be called, Lemon and Salt. I go heavy with both (I've been told I should have a T-shirt that says, "Needs Salt"), especially with this dressing and these ingredients.
You're going to like this salad. It's easy, it has character, and the textures work — soft dressing matched to soft and thinly sliced vegetables. It's a classic summer salad, but one to use during winter to remind you what to look forward to.
This is the time to go with canned olives — you want a muted olive flavor that won't overpower the delicate lettuce. Leave the olives whole so you can stick 'em on your fingers like you did as a kid.
Combine the oil, lemon juice, basil, and vinegar in a bowl and whisk together (or whip it up with a fork in a tall glass). Season to taste with salt and pepper (don't be afraid to go heavy on the salt). In a serving bowl, combine the lettuce with the remaining ingredients, then add the dressing. Toss to combine. Let stand 5 minutes. Serve.