Make the mirepoix: Heat the oil in a large saucepan over medium-high heat. Cook the onion, carrots, and celery for about 5 minutes, or until just tender.
Cook aromatics: Add the garlic, oregano, cumin, paprika, and cayenne. Cook for 1 minute more.
Add liquid and lentils: Add the tomato paste and cook for another minute, stirring constantly. Mix in the vegetable broth, diced tomatoes, and red lentils.
Add cabbage: Mix in the cabbage in batches, pressing each batch down to submerge it in the liquid.
Simmer: Bring to a boil before reducing the heat. Simmer covered for 20 minutes, stirring occasionally.
Season and garnish: Add the lemon zest and juice. Season with salt and pepper to taste. Garnish with parsley for serving.
