This slow cooker 4-ingredient onion soup corned beef is the kind of meal my husband asks for all month long. It’s rich, savory, and the meat practically falls apart when you lift it with a fork. Using a packet of onion soup mix gives you that deep, intense flavor without any fuss, and everything cooks together in one pot. It’s perfect for busy days, Sunday dinners, or anytime you want a cozy, comforting roast that tastes like you fussed over it all afternoon—without actually doing that.
Serve the tender corned beef sliced or shredded right out of the slow cooker with the soft potatoes and plenty of that rich oniony broth spooned over the top. A simple green side salad or steamed green beans balances the richness nicely. Buttered crusty bread or dinner rolls are great for soaking up the juices. If you like, add a little prepared horseradish or grainy mustard on the side for the grown-ups. Leftovers make wonderful sandwiches the next day on toasted rye or buns, with a bit of the onions tucked in for extra flavor.
Slow Cooker 4-Ingredient Onion Soup Corned BeefServings: 6
Ingredients
3–3.5 lb corned beef brisket with seasoning packet, rinsed and patted dry
1 (1 oz) packet dry onion soup mix
1.5–2 lb small potatoes, scrubbed and quartered
2 cups low-sodium beef broth or water
Directions
Place the quartered potatoes in an even layer on the bottom of a 6-quart slow cooker. This creates a bed for the meat and lets the potatoes soak up all the savory juices.
Set the corned beef brisket on top of the potatoes, fat side up. Sprinkle the seasoning packet that came with the brisket evenly over the meat.
Sprinkle the dry onion soup mix over the top of the corned beef, letting some fall down around the sides onto the potatoes. This is where most of the deep, savory flavor comes from.
Pour the beef broth (or water) around the edges of the meat, being careful not to wash all the seasoning off the top. You want the liquid to come about halfway up the sides of the brisket.
Cover the slow cooker with the lid and cook on LOW for 8–10 hours, or on HIGH for 4–5 hours, until the corned beef is very tender and easily pulls apart with a fork and the potatoes are soft.
Once done, carefully lift the corned beef out onto a cutting board. Let it rest for 5–10 minutes so it holds together better, then slice or shred against the grain.
Stir the potatoes and onions in the slow cooker so they’re coated in the rich broth. Return the sliced or shredded corned beef to the slow cooker on top of the potatoes, spoon some of the oniony juices over the meat, and serve directly from the pot so everything stays warm and cozy.
Variations & Tips
For extra veggies, you can tuck thick chunks of peeled carrots or wedges of cabbage in with the potatoes, as long as you don’t overcrowd the slow cooker. If your family prefers a slightly sweeter roast, add 1–2 tablespoons of brown sugar on top of the meat with the onion soup mix. For picky eaters who aren’t sure about strong flavors, use water instead of beef broth and choose a lower-sodium corned beef, then let them add a little extra salt at the table if needed. If you like things a bit tangy, stir in 1–2 tablespoons of Dijon or grainy mustard into the cooking liquid during the last hour. Leftovers keep well for 3–4 days in the fridge and reheat nicely in a covered dish with a splash of the broth. You can also shred leftover meat and potatoes together and crisp them in a skillet for an easy next-day hash topped with fried eggs for breakfast or a simple supper.
