Slow-Cooker Black Pepper Steak with Bell Peppers

This saucy Chinese black pepper steak brings the bold, peppery punch of your favorite wok spot right to your slow cooker.

Tender strips of sirloin simmer low and slow in a glossy oyster sauce glaze, then get a fresh crunch from tri-color bell peppers in the final half hour. It's a dump-and-go dinner that fills the kitchen with an irresistible aroma.

Forget takeout — this slow-cooker black pepper steak delivers deep, savory flavor with minimal effort. Sirloin strips cook gently in a rich sauce of oyster sauce, dark soy, Shaoxing wine, and plenty of cracked black pepper.

The slow cooker does the work while you go about your day, and the bell peppers add a bright finish that keeps every bite lively. Serve it over steamed rice for a complete meal that feels special any night of the week.

Ingredients

Why this recipe works

The slow cooker is the secret to tender, juicy steak without a wok. Low, moist heat gently breaks down the muscle fibers in sirloin, turning it fork-tender while the sauce concentrates and thickens.

Unlike quick stir-frying, this method forgives timing mistakes and delivers consistent results every time.

Adding the bell peppers in the final 30 minutes preserves their crisp texture and vibrant color. If they went in at the start, they would turn mushy and dull. This two-stage cooking approach gives you the best of both worlds: soft, saucy meat and crunchy peppers in the same bite.

Notes and substitutions

Top sirloin is ideal here because it has enough marbling to stay moist during long cooking, yet it's lean enough to not become greasy. Slice it thinly against the grain for the most tender results. If you prefer, flank steak or round steak also work well — just keep the slices thin and even.

Oyster sauce is the backbone of the glaze; it brings sweetness, saltiness, and a deep umami note. Dark soy sauce adds color and richness, while Shaoxing wine provides a subtle aromatic complexity.

Coarsely cracked black pepper is essential — pre-ground pepper won't give the same bold, fragrant punch. For a gluten-free version, use tamari instead of dark soy and ensure your oyster sauce is gluten-free.

• top sirloin steak: flank steak or round steak, sliced thin
• oyster sauce: hoisin sauce mixed with a splash of water (for a vegetarian version, use mushroom sauce)
• dark soy sauce: regular soy sauce (use 1 1/2 tbsp)
• Shaoxing wine: dry sherry or chicken broth

Equipment

• 6-quart slow cooker (Crockpot)
• Cutting board
• Chef's knife
• Measuring spoons
• Measuring cups
• Wooden spoon or spatula
• Tongs
• Small bowl