Start the base: Put a large soup pot or Dutch oven on the stove over medium heat.

Add the olive oil to the pot and let it heat for about 30 seconds.

Add the chopped onion, diced carrots, and diced celery to the pot. Cook, stirring every minute or so, for 6 to 8 minutes, until the onion looks soft and the vegetables have started to release moisture.

Add the sliced garlic to the pot. Cook for 1 minute, stirring often, until it smells fragrant.

Add the sliced cabbage to the pot. Stir it in and cook for 4 to 5 minutes, until it wilts and the volume drops by about half.

Add the rinsed lentils to the pot. Stir for about 30 seconds so the lentils are coated with the oil and vegetables.

Pour the vegetable broth into the pot. Scrape the bottom of the pot with a wooden spoon so nothing is stuck there.

Raise the heat to high and bring the broth to a full boil.

Simmer the lentils: Lower the heat to maintain a gentle simmer. Set the lid on the pot partway and cook for 20 minutes.

Remove the lid and stir in the drained chickpeas. Keep the stew at a gentle simmer.

Cook for 8 to 12 minutes more, stirring once or twice, until the lentils are tender but still holding their shape and the broth looks slightly thicker.

Finish the stew: Put the Dijon mustard and red wine vinegar in a small bowl. Ladle in about 2 tablespoons of hot broth and stir until smooth.