Warm up a skillet over medium-high heat.
Brown the beef cubes in the skillet for about 1 minute per side.
1 lb. beef cubes for stewing
Transfer the meat to a slow cooker.
Add all the remaining ingredients, except for the spinach and the mushrooms, to the slow cooker.
1 butternut squash, 1 medium onion, 3 garlic cloves, 4 carrots, 1 cup chicken stock, 14 oz. diced tomatoes, 1 tbsp. chili powder, 1 tsp. paprika, 1 tsp. dried oregano, Sea salt and freshly ground black pepper
Give everything a good stir, set the slow cooker to low, and cook for 6 hours.
Add in the mushrooms 30 minutes before the stew is done.
6 oz. mushrooms
Add the spinach just before serving.
6 oz. spinach