Heat the olive oil in a large pot or Dutch oven set over medium heat. Add the onions and cook for 2-3 minutes, or until just starting to soften. Add the finely chopped carrots and celery and sprinkle with a pinch of salt. Mix well and cook for 8-10 minutes, or until the vegetables have softened.
Add the minced garlic and mix well to combine, then add the ground cumin, oregano, paprika, salt, and black pepper. Mix well and continue to cook for 1 minute.
Add the tomatoes, lentils, and either water or vegetable broth into the pot, adding between 6 to 8 cups depending on your preference for a thicker or more broth-like stew. Stir thoroughly, then turn the heat up to high to bring the mixture to a boil. Once boiling, reduce the heat to low.
Combine the diced chipotles in adobo sauce with the tomato paste. This recipe calls or 5-7 chipotle peppers in adobo sauce. For a more mild stew, start with 1-2 chipotle peppers and add more to taste.
Stir in the chipotle and tomato paste mixture, mixing well. Cover and simmer for 30 minutes, stirring occasionally.
Stir in the butternut squash and continue to cook for an additional 30-45 minutes, or until the lentils are cooked and the butternut squash is tender.
Approximately 10 minutes before serving, stir in the chopped kale and mix well to combine.
Remove from heat and season to taste. Serve with your favorite garnishes, such as sour cream, mozzarella cheese, fresh parsley or cilantro, chopped green onions, sliced avocado, lime juice, and Tabasco sauce.