In a small bowl, toss the tomatoes and cucumbers with a pinch of the salt and freshly ground pepper. Add to the lettuce bowl.
In the same small bowl, toss the avocado and lime juice together until coated, then add to the lettuce bowl.
In the same small bowl, whisk together the grated garlic clove with Dijon mustard, then add in the red wine vinegar and whisk until garlic is mostly dissolved. Slowly whisk in the olive oil and seasoning with the remaining salt and pepper.
Add to the lettuce bowl and toss well, then toss again with the salad toppers. Taste, adding more salt and pepper as desired and serve immediately.