1. Place cardamom and cumin in a large saucepan over medium heat; cook 5 minutes or until toasted, stirring occasionally. Add 3 cups water, broth, and bay leaf; bring to a boil. Reduce heat to low; simmer 40 minutes. Strain mixture through a sieve over a bowl, reserving liquid. Discard solids.
2. Combine cooking liquid and lentils in pan; bring to a boil. Remove from heat; cover. Let stand 18 minutes or until lentils are just tender; drain.
3. Heat olive oil in a large skillet over medium-high heat. Add shallots; sauté 2 minutes or until tender. Add garlic; cook 1 minute, stirring constantly. Add lentils, 1/4 teaspoon salt, and pepper. Remove from heat; set aside.
4. Prepare grill to medium-high heat.
5. Arrange fish on grill rack coated with cooking spray; grill 4 minutes or until skin is crisp. Turn; grill 3 minutes or until desired degree of doneness. Remove from grill. Sprinkle with remaining 1/4 teaspoon salt; drizzle with juice.
6. Combine greens and vinegar. Arrange 1 cup greens on each of 4 plates; top each with 1 cup lentils. Arrange 3 sardines on each plate.