Heat 1 1/2 teaspoons Ghee in a large saucepan over medium heat.
Add onion, carrot, and garlic; cook 5 minutes. Stir in broth and next 7 ingredients (through peas); bring to a boil. Cover, reduce heat, and simmer 1 hour, stirring occasionally.
Place mustard and cumin seeds in a large nonstick skillet over medium heat; cook for 1 minute or until toasted.
Add remaining 3 tablespoons Ghee; cook 1 minute or until seeds begin to pop. Stir into soup; serve immediately.