Dinner · Part 3 of 3: Tips & recipe card

Crockpot Portobello Butter Bottom Round Roast Tips, FAQ & printable recipe

Name: Crockpot Portobello Butter Bottom Round Roast
Prep time: 10 min
Cook time: 8 h
Total time: 8 h 15 min
Cuisine: American
Ingredients: 3 1/2 lb beef bottom round roast; 8 oz portobello mushrooms, thickly sliced; 2 tbsp minced garlic; 1/2 cup salted butter (1 stick)

By Clara Weller · Oct 28, 2026

Fork-tender beef roast with portobello mushrooms in a buttery jus in a slow cooker

Prep: 10 min
Cook: 8 h
Total: 8 h 15 min
Serves: 6

Includes 5 min resting

Tips for success

For the most tender result, cook on LOW rather than HIGH. Bottom round is lean and needs gentle heat to break down without drying out.

If you're short on time, cook on HIGH for 5 to 6 hours, but check for tenderness early. The meat is done when it shreds easily with a fork.

Let the roast rest for at least 3 minutes after cooking. This allows the juices to settle back into the meat, making every slice moist.

If you're shredding, do it right before serving to keep it warm. The jus can be thickened with a cornstarch slurry if you prefer a gravy-like consistency.

Variations

Herb-Butter Roast: Add 1 teaspoon dried thyme and 1 teaspoon dried rosemary to the butter before placing it on the roast. The herbs infuse the jus with an aromatic, savory note.
Onion and Mushroom: Layer 1 large sliced yellow onion under the roast, and increase the mushrooms to 12 ounces. The onions soften and sweeten the jus as they cook.
Red Wine Jus: After cooking, stir 1/4 cup red wine into the jus and simmer for 5 minutes on the stovetop. The wine adds depth and a slight tang.
Garlic Lover's: Increase the minced garlic to 3 tablespoons, and add 4 whole peeled garlic cloves to the pot. The cloves become sweet and spreadable.

Storage and make-ahead

Fridge: Store in an airtight container in the refrigerator for up to 4 days. Cool within 2 hours of cooking.
Freezer: Freeze in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator before reheating.
Reheat: Reheat gently on the stovetop over low heat, adding a splash of water or broth to loosen the jus. Microwave in 30-second bursts, stirring between.

Refrigerate leftover beef and jus in an airtight container for up to 4 days. Cool to room temperature within 2 hours of cooking before refrigerating. Reheat gently on the stovetop or in the microwave, adding a splash of water if the jus has thickened.

This recipe is ideal for making ahead. Assemble the ingredients in the slow cooker insert the night before, cover, and refrigerate.

In the morning, place the insert in the slow cooker and cook as directed. The cook time may increase by 30 minutes if starting from cold.

Serving ideas

Serve the beef over whipped Yukon Gold mashed potatoes, with the jus spooned generously over the top. The buttery gravy soaks into the potatoes, making each bite rich and comforting. Add a side of green beans or a simple salad to brighten the plate.

The sliced roast also works well in sandwiches, piled onto crusty rolls with a spoonful of jus for dipping.

Leftovers can be chopped and folded into a hearty hash with potatoes and onions. The mushrooms are delicious alongside, adding a meaty, earthy note.

Frequently asked questions

Can this recipe be made with a different cut of beef?

Yes, chuck roast or brisket are excellent substitutes. They have more marbling, which makes them even more forgiving. Adjust the cooking time as needed—chuck may cook faster, so check for tenderness after 7 hours.

Why is the roast dry after cooking?

A dry roast usually means it was cooked too long or on high heat. Bottom round is lean, so it needs low, slow cooking. Always check the internal temperature—at least 145°F (63°C)—and remove it from the slow cooker once it's fork-tender.

Can this be frozen?

Yes, freeze the cooked beef and jus in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator and reheat gently on the stovetop or microwave. The texture remains tender after thawing.

What can be served with this roast?

Mashed potatoes are a classic choice, but the jus also works well over egg noodles, rice, or polenta. Roasted carrots or green beans add color and freshness to the plate.

Can the cooking time be shortened?

Yes, cook on HIGH for 5 to 6 hours, but check for tenderness early. The meat is done when it shreds easily with a fork and reaches 145°F (63°C). Low heat is still recommended for the most tender result.

Recipe card

Crockpot Portobello Butter Bottom Round Roast

Prep 10 minCook 8 hRest 5 minTotal 8 h 15 minServes 6

Ingredients

3 1/2 lb beef bottom round roast
8 oz portobello mushrooms, thickly sliced
2 tbsp minced garlic
1/2 cup salted butter (1 stick)

Instructions

Place the beef bottom round roast in the center of a 6-quart slow cooker. There is no need to sear or season—just set it in the insert.
Scatter the thickly sliced portobello mushrooms over and around the roast. Sprinkle the minced garlic evenly over the top.
Place the whole stick of salted butter on top of the roast and mushrooms. It will melt and baste the meat as it cooks.
Cover the slow cooker and cook on LOW for 8 to 10 hours, until the roast is fork-tender and easily pulls apart. Do not open the lid during cooking. Let it rest for 3 minutes before slicing.
After 8 hours, check that the internal temperature of the roast reaches at least 145°F (63°C). Remove the roast to a cutting board and let it rest for at least 3 minutes before slicing or shredding.
Slice the roast against the grain into thick pieces, or shred it with two forks. The meat should be very tender and pull apart easily.
Stir the braising liquid in the slow cooker to combine the melted butter, mushroom juices, and garlic. Spoon the jus over the sliced or shredded beef before serving.

Contains: milk

Estimated nutrition per serving

Calories: 540
Protein: 45 g
Carbohydrates: 4 g
Fat: 38 g

Automatic estimate from the ingredient list, not laboratory-verified.

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This recipe is based on a short cooking video and is published under the pen name Clara Weller. It was checked before publication, but errors can slip through. Nutrition, when shown, is an estimate. Read more in our editorial policy and on our food safety page.