Short Ribs With Natural Gravy

Brush mustard on surface of ribs. Place flour in a shallow dish. Coat ribs with flour, shaking to remove excess.

In a pressure cooker, heat oil. Add ribs and saute in hot oil, turning to brown on all sides. Remove and set aside.

Add leeks and parsley and saute in hot oil for 2 minutes. Stir in tomatoes, broth, sherry, brown sugar, salt, pepper and tarragon.

Add ribs. Secure lid. Over high heat, develop steam to high pressure. Reduce heat to maintain pressure and cook for 18 minutes.

Release pressure according to manufacturer's directions. Remove lid. Add carrots and potatoes to rib mixture. Secure lid. Over high heat, develop steam to high pressure. Reduce heat to maintain pressure and cook for 6 minutes.

Release pressure according to manufacturer's directions. Remove lid. Transfer ribs and vegetables to a platter.

Combine sour cream, butter, and potato starch, blending until smooth. Gradually add to cooking liquid, stirring and cooking over medium heat for 1 minute.

Spoon sauce over ribs and vegetables.