In a medium lidded pot, combine lentils, bay leaf, thyme sprig and 6 cups lightly salted water; bring to a boil. Reduce heat to medium-low and simmer 20 to 25 minutes until lentils are tender (they should be slightly firm, not mushy). Drain and remove herbs.
Meanwhile, heat 2 tbsp of the oil in a large sauté pan over medium heat. Add fennel, onion, carrot and celery. Cook 10 minutes or until softened. Add garlic; cook 2 minutes. Stir in drained lentils, remaining 1 tbsp oil, the vinegar, mustard, salt and pepper.
Prepare chicken sausage per package directions. Slice on the bias in 1/4-inch pieces. Serve over lentils. Garnish with parsley, if desired.
Potassium-rich fennel offers a way to regulate blood pressure.
