In a large saucepan over medium-high heat, add 3 tablespoons oil. Add garlic, shallot, thyme and barley; cook for 2 to 3 minutes until softened. Mix well. Add chicken stock and bring mixture to a boil. Cover and reduce heat to low. Cook for 30 minutes until barley is tender and liquid is absorbed. Remove sprigs of thyme. Fold in currants and parsley.
Remove barley to a parchment lined sheet tray. Allow to cool completely in refrigerator. Once cooled, add barley mixture to a bowl. Mix in flour and egg. Form mixture into 3-inch patties and place on a platter.
In a large saute pan over medium high heat, add remaining oil. Sear cakes for 1 to 2 minutes on each side. Remove from pan and serve.