Add all Dressing ingredients to a blender and blitz until smooth and creamy. Taste and add salt and pepper, as needed.
Roughly chop romaine or mixed greens. Toss together with croutons and parmesan. Drizzle with dressing and toss to coat (you may not need all of the dressing).
To make croutons, cut or tear bread into pieces, then drizzle with oil (1 tablespoon of oil per cup of bread). Season with salt and pepper, then saute in a pan on the stove until golden brown and crispy.