Crock-Pot Lentil Soup is a simple yet elegant dish prepared in a slow cooker. French lentils are simmered with chopped vegetables for a hearty and wholesome appetizer.
In a microwave-safe bowl, combine 2 tablespoons extra-virgin olive oil, 1 cup diced red onion,½ cup diced celery,¾ cup diced carrots,1 tablespoon minced garlic, and 1 teaspoon dried herbs de Provence. Heat in the microwave on high power for 5 minutes, stirring halfway through.
Transfer vegetable mixture, 1 cup French lentils or lentils du puy, 1 (14.5-ounce) can diced tomatoes with juice, 8 cups vegetable broth or stock, ½ teaspoon kosher salt, and ¼ teaspoon black pepper to a 6-quart slow cooker.
Cover and cook until lentils are tender, 4 to 6 hours on HIGH or 7 to 9 hours on LOW.
Add the 1 ½ cups sliced brown mushrooms and 4 cups chopped kale, to the lentil soup. Cover and cook on high setting for 30 minutes.
Taste the soup and season with salt and pepper as desired. Serve soup hot garnished with 1 tablespoon chopped parsley.