How to Make It
In a large deep skillet, heat 1 tablespoon each of the butter and olive oil over medium-high heat. Season the roast generously with salt and black pepper. Add the roast to the skillet, and cook until richly golden brown and seared on all sides, about 15 minutes. Pour in the beer and deglaze, scraping up the bits from the pan, about 3 minutes. Transfer the roast and beer to a slow cooker.
Add the onions, garlic, beef broth, liquid aminos, and bay leaves to the slow cooker and cover and cook on high for 4 hours or on low for 8 hours. In the final 20 minutes of cooking, turn the cooker to low and add the kale. Cover and cook for 20 more minutes until the kale is bright green and tender.
Transfer the meat to a cutting board, cover with foil and keep warm. Pour the contents of the sauce into a colander set over a heatproof bowl and discard the bay leaves. Transfer the kale and onions to a bowl and keep warm.
Skim the fat off the surface of the sauce. In a small bowl combine the flour and 1 tablespoon of room temperature butter together until a smooth paste forms. In a medium saucepan, bring the cooking liquid to a boil and whisk in the butter paste, whisk until the gravy is thickened, about 8 minutes.
Slice the meat and arrange on a large platter. Scatter the kale and onions around the roast and pour the gravy over the top. Serve with buttered egg noodles and horseradish.