I use small amounts of demi-glace. Watered down it is like a meaty aus juice. I usually make my own in huge vats several times a year from roasted meat or poultry, reduce, and freeze in ice cube trays.
But, D’Artagnan Demi Glace is excellent. Usually found in the meat section in my local supermarkets. Pricey, but worth it, like most of their products.
http://www.dartagnan.com/DemiGlace.html
Also, if you can find it, Knorr makes a condensed “Home Style Stock” that is ok. Better than BTB or any other brands of similar products. You can usually get some good stuff at restaurant supply stores. Or if you are friends with a restaurant owner, they can order stuff for you.
http://www.knorr.com/product/category/245804/homestyle-stock
