Chop onion, zucchini, yellow squash, and kale. Seed and mince serrano pepper.
Place chopped onion, garlic, serrano pepper, 3/4 tsp of salt, and 1/2 tsp of black pepper in a container.
Place chopped zucchini and yellow squash in another container
Place chili powder, cumin, garlic powder, 1 1/4 tsp of salt, and 1/2 tsp of black pepper in a smaller container.
Heat olive oil and butter in covered pot over medium heat, until butter melts. ~1 minute.
Add onion, garlic, serrano pepper, salt, pepper to pot. Cook, stirring occasionally until onion is softened. ~3 minutes.
Stir in zucchini and yellow squash. Cook, stirring often, until softened. ~3 minutes.
Add ground beef, chili powder, cumin, garlic powder, salt, and black pepper. Stir to crumble beef. ~1-2 minutes.
Cover pot and cook, stirring occasionally until beef is cooked through. ~3-5 minutes.
Stir in chicken stock, beans, and lentils. Increase heat to high and bring to boil.
Reduce heat to low; cover and cook, stirring occasionally until lentils are softened. ~25-30 minutes.
Stir in crushed tomatoes; cover and simmer on low, stirring occasionally. ~20 minutes.
Stir in kale until wilted. Cook, stirring occasionally. ~25 minutes.