Crockpot Portobello Butter Bottom Round Roast

This Crockpot bottom round roast is the definition of set-it-and-forget-it. A handful of ingredients—beef, portobellos, garlic, and a whole stick of butter—go into the slow cooker in minutes.

Hours later, the meat is fork-tender and swimming in a rich, buttery jus. Serve it over mashed potatoes for a dinner that feels like a Sunday supper, even on a busy weeknight.

Bottom round roast is a lean, economical cut that rewards long, slow cooking. Here, it simmers all day with thick portobello slices, minced garlic, and salted butter.

The butter melts into a golden jus that bastes the beef and mushrooms as they cook. The result is a deeply savory, comforting meal with almost no hands-on time. Just layer the ingredients, cover the slow cooker, and let it work.

Ingredients

Why this recipe works

Slow cooking breaks down the connective tissue in a bottom round roast, turning a tough cut into spoon-tender meat.

The low, steady heat of the Crockpot allows collagen to melt into gelatin, which gives the meat its silky texture and enriches the cooking liquid. Because the roast is cooked in its own juices, it never dries out.

The butter serves a dual purpose: it adds rich flavor and creates a self-basting sauce. As it melts, it coats the mushrooms and garlic, infusing them with savory depth.

The high moisture environment of the slow cooker ensures the mushrooms stay plump and meaty, and the resulting jus is glossy and full of umami.

Notes and substitutions

Choose a bottom round roast that fits comfortably in your slow cooker. If it's too large, trim it or cut it into two pieces. Portobello mushrooms should be thickly sliced so they hold their texture after hours of cooking. Minced garlic adds a punch of flavor; for a mellower note, use whole cloves.

Salted butter is specified because it seasons the jus as it melts. If you only have unsalted, add about 1/2 teaspoon of salt to the pot before cooking. A 6-quart slow cooker works best; if yours is smaller, adjust the roast size. No searing is needed—the slow cooker does all the work.

• beef bottom round roast: chuck roast or brisket
• portobello mushrooms: cremini or white button mushrooms
• salted butter: unsalted butter plus 1/2 tsp salt
• minced garlic: 2 garlic cloves, finely grated

Equipment

• 6-quart slow cooker
• Measuring spoons
• Cutting board
• Chef's knife
• Serving spoon