Fast, Rich Pressure-Cooker Beef Stock

• 2 tablespoons tomato paste
• 3 pounds meaty beef marrow bones
• 2 1/2 pounds (1-inch-thick) beef shanks
• 2 celery stalks, diagonally cut into 2-inch pieces
• 1 large carrot, peeled and diagonally cut into 2-inch pieces
• 1 large onion, peeled and cut into 8 wedges
• Cooking spray
• 1 tablespoon black peppercorns
• 2 bay leaves
• 1/2 bunch fresh flat-leaf parsley
• 8 cups cold water

1. Preheat oven to 500u0b0.
2. Brush tomato paste evenly over bones and shanks; place in a large roasting pan. Add celery, carrot, and onion to pan; lightly coat with cooking spray. Bake at 500u0b0 for 30 minutes.
3. Transfer bone mixture to a 6- or 8-quart pressure cooker; add peppercorns, bay leaves, and parsley. Pour 8 cups water over mixture. Close lid securely, and bring to high pressure over high heat. Reduce heat to medium or level needed to maintain high pressure; cook for 35 minutes. Remove from heat; release pressure through steam vent, or place cooker under cold running water to release pressure. Remove lid, and let stand for 20 minutes. Strain stock through a cheesecloth-lined sieve into a large bowl, pressing solids to release excess moisture. Discard solids. Cover and chill overnight. Skim solidified fat from surface; discard.
4. Note: Refrigerate stock for up to 1 week or freeze for up to 3 months.

tomato paste, beef marrow, beef shanks, celery stalks, carrot, onion, cooking spray, black peppercorns, bay leaves, parsley, cold water

Taken from www.myrecipes.com/recipe/fast-rich-pressure-cooker-beef-stock (may not work)