01 -
Pat beef cubes dry with paper towels to remove moisture, then season evenly with salt and pepper on all sides.
02 -
Heat a skillet over medium-high heat and sear beef cubes in batches until browned on all sides, about 3 minutes per batch. Transfer to slow cooker.
03 -
In a bowl, whisk together beef broth, soy sauce, Worcestershire sauce, brown sugar, tomato paste, minced garlic, smoked paprika, salt, and pepper until smooth.
04 -
Place beef cubes evenly in the slow cooker. Pour sauce mixture over beef. Add optional vegetables if using, arranging around the meat.
05 -
Cover and cook on low for 6 to 8 hours or on high for 3 to 4 hours, until beef is fork-tender.
06 -
In the last 30 minutes, taste and adjust seasoning. If desired, stir in cornstarch slurry and cook for another 15 minutes to thicken.