Brown beef bones and boil. Keep covered with water for 8 to 10 hours. Strain, reserving liquid.
Put beef bones in pot with chicken bones, vegetables and seasonings. Cover with water and cook 4 to 5 hours. Strain. Reserve liquid.
Combine the second liquid with the first. Add tomato puree. Strain. Reduce until liquid will coat a spoon. Skim throughout reduction.
Note: Reduction works best in a tall pot on low heat.
Refrigerate between steps to bring fat to top and strain.
Leftover demi-glace may be frozen in ice cube trays for future use.
Submitted by: Sally
