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 olive oil, onion, celery, carrots, garlic, and herbs de Provence. Heat in the microwave on high power for 5 minutes, stirring halfway through.
Transfer vegetable mixture, lentils, diced tomatoes with juice, vegetable broth, salt add pepper to a 6-quart slow cooker.
Cover and cook until lentils are tender, 4 to 6 hours on high setting, or 7 to 9 hours on low setting.
Add the mushrooms and 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.