Begin by chopping your onion, carrots, and celery into bite-sized pieces, and mince the garlic finely. If using beef stew meat, cut it into 1-inch chunks for even cooking.

Add the beef chunks, rinsed lentils, chopped onions, carrots, celery, minced garlic, and diced tomatoes to the slow cooker. Pour in the beef or chicken broth, then sprinkle in the smoked paprika, ground cumin, dried thyme, and bay leaf. Stir gently to combine.

Cover the slow cooker and set it to cook on low heat for 8-10 hours or on high heat for 4-6 hours, until the beef is fork-tender.

Once cooked, taste the stew and adjust the seasonings with salt and black pepper if needed. Carefully remove the bay leaf.

Ladle the stew into bowls, and serve with warm crusty bread or rice.