Rinse lettuce, pat dry with paper towels or a clean kitchen towel, then slice into 1 ½-inch sections.
Rinse cherry tomatoes, then pat dry and slice in half.
Cut avocado in half, remove the pit, then slice through the flesh to make cubes that you can peel off the skin.
Cut cucumber into slices or bite-sized pieces.
To make the vinaigrette, whisk together red wine vinegar and dijon mustard, then slowly whisk in oil. Season to taste with salt and pepper.
Arrange lettuce, tomatoes, cucumbers, and avocado onto 4 small plates.
Sprinkle each with shredded parmesan cheese and croutons.
Drizzle with dressing, and serve.
Notes
Make-Ahead Tips: You can make the red wine vinaigrette in advance, and prep the cucumbers, cherry tomatoes, and lettuce. Keep the lettuce in damp paper towels in the refrigerator until you’re ready to assemble. The avocado chunks will brown if you cut them more than a half hour or so in advance. And the whole salad can get soggy if it is assembled and dressed ahead of time.Expert Tips: If you are serving a large gathering, you can double or triple this recipe.You can take the vinaigrette a little farther by adding either fresh or dried herbs, or adding a little honey for sweetness. Store in an airtight jar in the refrigerator and shake well before using.Want to make your own croutons? Just cube day-old bread and toss with olive oil, salt, and pepper. Then toast in the oven or in a large skillet until lightly browned and crispy.Rinse the romaine lettuce well, and make sure to pat dry as much as possible. Lettuce with water on it will make the rest of the salad soggy. You might try putting it in a salad spinner as well to really remove any extra liquid.