Prep the Roasts
Cut small slits all over each roast and stuff with garlic cloves.
Coat all sides with garlic powder, onion powder, and Cajun seasoning.
Set Ninja Foodi to Sear/Sauté. Add tallow or oil and sear roasts on all sides. Remove and set aside.
Add Guidry’s mix to the pot. Stir and scrape up browned bits.
Pour in beef broth and return both roasts to the pot.
Switch to Braise mode. Cover and cook for 4 hours.
Add baby potatoes and carrots. Continue braising for 2 more hours, until fork-tender.
Whisk in a gravy packet during the last 15–20 minutes for a thicker sauce.
Spoon tender roast, vegetables, and broth into bowls. Serve hot.