Put everything into the blender and process until smooth. If you like a chunky texture, add crumbled blue cheese after the processing. Pour into a container and refrigerate for 1 to 2 weeks. Makes about 2 cups.
Notes
When buying the blue cheese, buy a wedge or block of it and not the packaged crumbles.
Whole-milk cottage cheese and buttermilk is recommended
For a chunky texture, use a fork to break off chunks from the wedge and add after the dressing has been blended.
Keep refrigerated in a lidded jar for up to 2-weeks