Cheesy Bacon Brussels Sprouts Au Gratin in the Slow Cooker Step-by-step instructions

Before you start

Before starting, trim and halve the Brussels sprouts. If using raw bacon, cook it until crispy, then drain and crumble. Mince the garlic. Shred the Gruyère if you bought it in a block. Have your 6-quart slow cooker ready. No need to preheat it; the slow cooker heats gradually as it cooks.

Instructions

Prep and Layer

1. 1Prepare the Sprouts and Bacon
   Trim the tough ends off the Brussels sprouts and cut each one in half through the core. If using raw bacon, cook it in a skillet over medium heat until crispy, then drain on paper towels and crumble into bite-size pieces. Mince the garlic cloves.
   Look for The sprouts are evenly halved and the bacon is crisp and crumbled.
   Tip For even cooking, choose sprouts that are similar in size. If some are very large, quarter them instead of halving.
2. 2Layer in the Crockpot
   Place the halved Brussels sprouts in the slow cooker. Sprinkle the crumbled bacon and minced garlic over the sprouts. Pour the heavy cream over everything, then sprinkle the shredded Gruyère on top. Stir gently to combine, making sure the sprouts are coated with cream.
   Look for All ingredients are evenly distributed and the sprouts are coated in cream.
   Tip Gently folding rather than vigorous stirring helps keep the bacon pieces intact and the cheese evenly spread.

The sprouts are trimmed and halved, the bacon is crispy and crumbled, and all ingredients are layered in the slow cooker. The cream should coat the sprouts, and the cheese sprinkled evenly on top.

The mixture looks colorful and inviting, with the white cream and golden cheese contrasting with the green sprouts and red-brown bacon bits.

Slow Cook and Transform

3. 3Slow Cook on Low
   Cover the slow cooker with the lid and set to LOW. Cook for 3 hours, until the Brussels sprouts are tender when pierced with a fork and the sauce is bubbling and golden around the edges. Stir once halfway through if possible, but avoid lifting the lid too often. Let it rest for 3 minutes before slicing.
   Look for The sauce is bubbly, the cheese is melted, and the sprouts are fork-tender.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Resist the urge to peek—each time the lid lifts, heat escapes and adds to the cooking time.

After 3 hours on low, the kitchen smells of garlic and bacon. The sauce is bubbling around the edges, the cheese has melted into a golden blanket, and the sprouts are tender when pierced with a fork.

The cream has thickened slightly, and the whole dish looks like a bubbling, cheesy casserole ready to serve.

Finish and Serve

4. 4Finish and Serve
   Once the sprouts are tender, give the gratin a gentle stir. Serve hot, spooning the creamy sauce over each portion. If desired, top with extra bacon or toasted breadcrumbs, though these are optional and not required for the dish.
   Look for The gratin is hot, creamy, and ready to serve.
   Tip For a golden top, you can place the slow cooker insert under the broiler for 2–3 minutes, but keep an eye on it.

The gratin is hot, creamy, and ready to be served. The sauce is rich and coats the sprouts, the cheese is gooey, and the bacon adds a smoky crunch. A spoonful holds together nicely, and the aroma is irresistible. Serve immediately, garnishing with extra bacon or breadcrumbs if desired.

Common mistakes

One common mistake is lifting the lid too often to check on the sprouts. Every time you lift the lid, heat escapes and can add 20–30 minutes to the cooking time. Another is overcrowding the slow cooker; if your sprouts are piled too high, they won't cook evenly.

Use a 6-quart or larger slow cooker. Also, don't skimp on the cream—it’s what creates the luxurious sauce. If the sauce seems too thin at the end, cook uncovered for an additional 15–20 minutes to reduce it.

How to tell it’s done

The gratin is done when the Brussels sprouts are tender enough to be pierced easily with a fork, but still hold their shape. The sauce should be bubbling and slightly thickened, and the cheese fully melted and golden around the edges.

If you used bacon, it should still have some texture—not soft. For food safety, if the dish contains bacon (which is pre-cooked), it doesn't require a minimum internal temperature, but the overall dish should be hot throughout, at least 165°F (74°C) for serving.

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