Guinness Onion Butter Bottom Round Roast: 5-Ingredient Slow Cooker Dinner

This slow cooker roast is the definition of set-it-and-forget-it. A well-marbled beef bottom round roast, pearl onions, a bottle of Guinness, and a stick of salted butter come together in the crockpot to create a deeply savory, fork-tender dinner.

The beer adds a malty, slightly bitter edge that balances the richness of the butter, while the onions turn sweet and jammy. Serve it over mashed potatoes or with crusty bread to soak up every last drop of the glossy, emulsified jus.

This recipe is built on a classic braising technique: low heat, plenty of liquid, and time. The beef bottom round roast is a lean cut that benefits from long, moist cooking, which breaks down the connective tissue and turns it meltingly tender.

The Guinness stout adds depth and a touch of roasted bitterness, while the pearl onions provide a sweet, mild onion flavor that complements the beef. The butter, added on top, melts and emulsifies into the cooking liquid, creating a rich, silky sauce that clings to every shred of meat. This is a no-fuss meal that delivers big flavor with minimal effort.

Ingredients

Why this recipe works

The slow cooker is the perfect vessel for this recipe. It maintains a gentle, consistent temperature that slowly renders the collagen in the beef bottom round, transforming a tough cut into spoon-tender meat. The low heat also allows the flavors of the Guinness, onions, and butter to meld and deepen without reducing too much, resulting in a luscious, concentrated jus that coats the meat beautifully.

The combination of Guinness and butter is a classic pairing that works wonders here. The stout's roasted, slightly bitter notes cut through the richness of the butter, while the butter adds a velvety mouthfeel and rounds out the beer's edge.

The pearl onions, cooked slowly in this liquid, become sweet and tender, absorbing all the savory flavors. This simple ingredient lineup creates a complex, satisfying dish that tastes far more involved than it is.

Notes and substitutions

Beef bottom round roast is a lean, budget-friendly cut that becomes incredibly tender with slow cooking. If you can't find it, beef chuck roast is an excellent substitute—it has more marbling and will also shred beautifully. Look for a roast that fits comfortably in your slow cooker insert, and don't worry about trimming excess fat; it will melt into the sauce and add flavor.

Guinness draught stout is the beer of choice here, but any dark stout or porter will work. The beer should be at room temperature when added.

Pearl onions are available pre-peeled in many grocery stores, saving time; if you buy them whole, blanch them in boiling water for 30 seconds and the skins will slip right off. Salted butter is specified to add seasoning to the sauce—if using unsalted, add a pinch of salt to the pot.

• beef bottom round roast: beef chuck roast or brisket (both work well, though cooking time may vary slightly)
• Guinness draught stout: another dark stout or porter, or use beef broth for a non-alcoholic version
• pearl onions: 1 large yellow onion, cut into wedges
• salted butter: unsalted butter plus 1/4 teaspoon salt

Equipment

• 6-quart slow cooker
• Cutting board
• Chef's knife
• Measuring cup
• Fork