In a large skillet, heat the oil over medium-high heat. Sauté the cabbage and carrots until softened and starting to brown, about 7 minutes. Add the garlic, salt and paprika. Continue to cook for a few minutes, until fragrant. Stir in the tomatoes and harissa, scraping up any brown bits that may have formed. Reduce the heat to medium-low and simmer for 5 minutes, or until the tomatoes have released some moisture and begun to soften. Fold in the white beans, butter or ghee, if using, and the kale. Cook for a few more minutes, until the greens have wilted but are still vibrant.