1. Almondaise sauce: add all the ingredients into a blender except the olive oil, and begin to blend.
2. Whilst the blender is running, drizzle the olive oil gradually into the puree until a smooth mixture is formed. If the puree is too stiff, add a little more oil or Alpro Almond Original.
3. Taste and adjust seasoning: you're the boss.
4. Assemble the open sandwiches: Spread each slice of bread with a generous dollop of the Almondaise sauce, then top with sliced avocado, watercress, sliced radishes and a sprinkle pepper on top. You can keep the remaining almondaise sauce in an airtight container in the fridge for a few days.
Need a gluten free version? Simply replace the bread with gluten free bread.