My sister made this for our Mother's Day brunch and everyone fought over the last slice. The butter sauce is absolutely divine

This slow cooker 4-ingredient shallot butter beef tenderloin is the kind of dish that makes a family gathering unforgettable. My sister first made it for our Mother’s Day brunch, and I still remember everyone crowding around the slow cooker, “just to taste” the sauce. By the time we sat down, folks were practically arguing over the last pink, buttery slice. It’s as simple as can be—just good beef, plenty of butter, sweet shallots, and a little salt—yet it tastes like something from a fancy restaurant. The slow cooker keeps the meat tender and juicy, while the shallot butter turns into a golden, spoonable sauce you’ll want to pour over everything on your plate.

Serve the tenderloin sliced into medallions right from the slow cooker, spooning the shallot butter sauce over the top. It’s lovely with buttery mashed potatoes, egg noodles, or a simple pan of roasted baby potatoes to catch every drop of that sauce. For a brunch table, pair it with scrambled eggs, a fresh green salad, and a basket of warm dinner rolls or biscuits for dipping. A side of steamed green beans or asparagus adds color and keeps things from feeling too heavy, and if you enjoy wine, a light red or a dry rosé fits this dish nicely.

Servings: 6

2 to 2.5 lb beef tenderloin roast, trimmed and tied

Pat the beef tenderloin dry with paper towels and let it sit at room temperature for about 20–30 minutes while you prepare the shallots. This helps it cook more evenly.

Peel and thinly slice the shallots. You want nice, thin slices so they soften and caramelize gently in the butter.

Scatter the sliced shallots evenly in the bottom of a 4- to 6-quart slow cooker. Sprinkle 1 teaspoon of the kosher salt over the shallots.

Lay the beef tenderloin on top of the shallots. Sprinkle the remaining 1 teaspoon of kosher salt all over the surface of the meat, gently pressing it in.

Dot the butter chunks all over and around the tenderloin, tucking some pieces down along the sides so they melt into the shallots. The butter will melt into a golden sauce as the meat cooks.

Cover the slow cooker and cook on LOW for 1.5 to 2.5 hours, depending on your slow cooker and how done you like your beef. Begin checking around 1.5 hours. For medium-rare, you’re aiming for an internal temperature of about 130–135°F in the thickest part of the roast.

Once the beef reaches your desired temperature, carefully lift the tenderloin onto a cutting board, tent it loosely with foil, and let it rest for 10–15 minutes. This helps the juices settle so every slice stays moist.

While the meat rests, give the shallot butter sauce in the slow cooker a gentle stir. The shallots should be soft, lightly caramelized, and floating in a rich, golden butter sauce. Taste and adjust the salt if needed.

Slice the rested beef tenderloin into 1/2- to 3/4-inch medallions. Return the slices to the warm slow cooker, nestling them into the shallot butter sauce so they’re coated and glistening.

Serve the medallions straight from the slow cooker, spooning plenty of the hot shallot butter and caramelized shallots over each portion. Expect everyone to eye that last slice—there usually isn’t any left.

For a peppery version, add 1 to 2 teaspoons of freshly ground black pepper along with the salt on the beef. If you’d like a hint of herb flavor without adding more ingredients, serve the finished dish with a sprinkle of whatever fresh herbs you have on hand (parsley or thyme are especially nice) instead of cooking them in the pot. To stretch the meal for a larger crowd, slice the tenderloin thinner and serve over toasted baguette slices or buttered noodles, letting the shallot butter act like a sauce. If you prefer a slightly more done roast, cook to 140–145°F for medium, but avoid going much higher or the tenderloin can dry out. For easier cleanup, you can line the slow cooker with a slow cooker liner, but remember that liners can make things cook a little faster, so start checking the temperature earlier. Food safety tips: Always thaw beef completely in the refrigerator, never on the counter. Use a meat thermometer to ensure the tenderloin reaches at least 130°F for medium-rare and 145°F if you want it fully safe by USDA standards. Do not leave cooked beef sitting at room temperature for more than 2 hours (or 1 hour if it’s a very warm day). Cool leftovers quickly, store them in shallow containers in the refrigerator, and enjoy within 3–4 days, reheating gently so the meat stays tender.