Heat the oil in a large pot (like a Dutch oven) over medium heat. Add the onions, carrot, and 1/4 teaspoon of salt and cook, stirring occasionally, until softened and starting to smell sweet, about 5-7 minutes. Stir in the garlic, cumin, coriander, black pepper, and turmeric and cook for 30 seconds.

Stir in the lentils and broth. Increase the heat to high and bring just to a boil. Taste then adjust with salt (we add between 1/2 and 1 teaspoon depending on how seasoned the broth is). Reduce the heat to a simmer and cook, partially covered, until the lentils are tender, 35-40 minutes.

Uncover and stir in the kale or spinach. Cook until wilted, about 5 minutes.

Stir in the juice of 1-2 lemons. Taste and adjust seasoning as needed.

Garnish with fresh herbs, if desired. Serve hot.