For the Spice Rub:
1. Combine 2 tablespoons each of cayenne pepper, cumin, dried rosemary. Add a generous pinch of coarse salt. Add 2 tablespoons of coffee granules and brown sugar.
2. Grind together with a mortar and pestle to make a spice rub.
For the Beef Brisket:
1. Place the seasoned brisket in an oven tray. Ensure all sides are sealed with the spice rub.
2. Add a generous amount of olive oil. Add chicken stock. Cover with foil and bake at 140/150°C for 4 to 5 hours.
3. Bring 1 cup barley and 2 1/2 cups of the brisket broth to a boil.
4. Reduce the heat to a simmer; cook, covered, until tender and most of the liquid has been absorbed, 20 to 25 minutes.
6. Let stand 5 minutes. Leave brisket to cool down.
7. Crumble the feta over the cooked lentils. Stir.
8. Gently tear the brisket into shards and pan fry for a few minutes to heat through and crisp a few edges.
9. Plate the brisket, pour over remaining juices and add the lentils. Serve immediately.