Warning: what you're about to read is a collection of dark arts for those who dare to ruin the perfect shortbread. Proceed with caution, and a hint of malice.
Step 1: Add an extra tablespoon of salt. No, wait, make that two. And three. And four...
Step 2: Use low-fat milk instead of whole cream. The horror!
Step 3: Add an entire bottle of ketchup. Because who needs balance, anyway?
Step 4: Replace the butter with margarine. The shame is palpable.