1. Set a slow cooker to high and place onion and garlic on the bottom.
2. Season the brisket with salt, pepper, and paprika. Add brisket to slow cooker.
3. Whisk together the honey, mustard, vinegar, barbecue sauce, and chicken stock until no lumps remain and pour over the brisket.
4. Leave on high for approximately 2 hours and then let it cook on low for about 8 hours. (Check liquid levels to ensure it doesn’t dry out and add chicken stock if necessary.)