Guinness Onion Garlic Butter Pork Sirloin Roast Step-by-step instructions

Before you start

Before starting, pat the pork sirloin roast dry with paper towels to help the seasoning adhere. If the roast is tied, leave it tied for even cooking. Peel the pearl onions if using fresh; to make peeling easier, blanch them in boiling water for 30 seconds, then plunge into ice water and slip off the skins.

Measure out the Guinness and have the cowboy butter ready. No other prep is needed — the slow cooker does the rest. Set out your serving plates and prepare the buttered noodles (or other sides) just before serving.

Instructions

Layer and Set

1. 1Layer the Roast and Onions
   Place the pork sirloin roast in the center of the slow cooker insert. Scatter the pearl onions around the roast. Pour the Guinness stout evenly over the meat and onions.
   Look for The roast sits in the middle with onions surrounding it, and the stout pools around the meat.
   Tip If the roast is larger than the insert, trim it to fit, but keep it whole for even cooking.
2. 2Top with Cowboy Butter
   Place the medallions of garlic-herb compound cowboy butter on top of the roast, spacing them evenly. Cover the slow cooker with the lid.
   Look for The butter sits in neat rounds on the roast, ready to melt into the braise.
   Tip If the butter is too cold to slice, let it sit at room temperature for 10 minutes before cutting.

In this phase, you simply assemble the ingredients in the slow cooker. The roast sits in the center, surrounded by pearl onions and bathed in stout. The butter medallions sit on top, ready to melt. There's no browning or sautéing required — just a quick layering of raw ingredients. The slow cooker is covered and set to LOW. The kitchen is quiet, but the promise of a rich, savory meal is already in the air.

Slow Cook and Shred

3. 3Cook Low and Slow
   Set the slow cooker to LOW and cook for 8 hours, or until the pork is fork-tender and shreds easily. Avoid opening the lid during cooking to maintain heat. Let it rest for 3 minutes before slicing.
   Look for The kitchen fills with a rich, malty aroma; the pork is deeply browned and tender.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip If time is short, cook on HIGH for 5–6 hours, but low heat yields the most tender results.
4. 4Shred the Pork
   Using two forks, shred the pork directly in the slow cooker. Stir the shredded meat into the cooking liquid so it soaks up the gravy. Let the meat rest in the liquid for 5 minutes before serving.
   Look for The pork pulls apart into long, moist strands; the liquid is thick and glossy.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip For extra-rich gravy, use a spoon to skim off excess fat after shredding.

After 8 hours, the slow cooker is bubbling gently, and the aroma of stout and garlic fills the kitchen. The pork is deeply browned and fork-tender, and the onions have softened into sweet, buttery bites. The liquid has reduced into a glossy, rich gravy.

Shredding the pork directly in the pot allows it to absorb the sauce, making every bite juicy and flavorful. This is the moment of transformation — the raw roast becomes a succulent, melt-in-your-mouth dish.

Serve and Savor

5. 5Serve with Buttered Noodles
   Spoon the shredded pork and onions over warm buttered egg noodles. Drizzle with extra gravy from the slow cooker. Serve immediately.
   Look for The pork is piled high on noodles, with glossy gravy coating every bite.
   Tip For a low-carb option, serve over mashed cauliflower or roasted vegetables.
6. 6Garnish and Enjoy
   If desired, sprinkle with fresh chopped parsley or chives before serving. This dish is best enjoyed warm, with extra gravy on the side.
   Look for A final garnish adds brightness to the rich, dark dish.
   Tip Store any leftovers in an airtight container in the refrigerator for up to 4 days.

The shredded pork is piled high over buttered egg noodles, with pearl onions nestled throughout. A ladle of gravy cascades over the top, and the dish is ready to serve. The texture is tender and moist, with a deep, malty flavor from the stout and a garlicky herb finish from the butter. This is comfort food at its finest — hearty, satisfying, and best enjoyed with good company. The leftovers are just as delicious the next day.

Common mistakes

One common mistake is lifting the lid too often to check on the roast. Every time the lid is raised, heat escapes and adds to the cooking time. Trust the process and keep the lid on. Another pitfall is using a lean cut without enough fat; if the roast is very lean, consider adding a few tablespoons of butter or oil to the pot.

Overcooking can dry out the meat, but the slow cooker's moist environment helps prevent that. Finally, don't skip the resting step after shredding — allowing the meat to sit in the gravy helps it stay juicy.

How to tell it’s done

The pork is done when it is fork-tender and shreds easily. The internal temperature should read at least 145°F (63°C) on an instant-read thermometer, but because the meat is cooked low and slow, it will likely be much higher — around 190°F (88°C) — which is ideal for shredding.

The onions should be soft and translucent, and the gravy should be thick and glossy. If the pork is still tough, continue cooking for another 30–60 minutes and check again.

• Steaks, chops and roasts: 145°F (63°C) in the thickest part, then a 3-minute rest