Homemade broths are easy to whip up with leftover bones and freeze well.
Place lamb bones in a stockpot. Pour in 12 cups cold water or enough to cover. Bring to a boil and skim off froth. Add remaining ingredients and simmer, partially covered, over low heat for 2 hours. Strain the broth through a fine sieve, discarding bone and vegetables. Let cool. Chill and skim off fat.
Make Ahead Tip: Cover and refrigerate for up to 2 days or freeze for up to 6 months.