In a food processor, mince garlic, tomato paste, coconut, curry powder, cumin, mustard and coriander seeds to make a paste.
Heat oil in a large saucepan over medium-high heat. Add onion. Cook, stirring, for 3 to 4 minutes or until softened. Add paste and cook for a minute.
Stir in stock, tomato and barley. Cover and bring to the boil. Reduce heat to low and simmer for 20 minutes.
Add red lentils and simmer covered for 25 minutes or until the barley is tender. Add water if soup appears too thick or to achieve desired consistency.
Stir in coconut cream, divide between bowls and top with coriander.