01 - Place the vegetable scraps in a large stockpot. Add bay leaves, peppercorns, thyme, and salt.
02 - Pour cold water into the pot, covering the scraps completely.
03 - Heat the mixture over high heat until boiling, then reduce to a gentle simmer.
04 - Simmer uncovered for 1 hour, occasionally skimming off any foam that forms on the surface.
05 - Remove from heat and allow to cool briefly before straining.
06 - Pour the broth through a fine-mesh sieve or cheesecloth into a large bowl or container, discarding solids.
07 - Taste and adjust salt if needed. Use immediately or cool completely before refrigerating for up to 5 days or freezing for up to 3 months.