Sautéed Beef with Caramelized Onions and Mushrooms

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · Published 2026-04-12 · Updated 2026-04-12

A savory, high-fat main course featuring tender beef strips cooked with sweet onions and earthy mushrooms in a rich garlic-infused sauce. This american-inspired beef (low-carb) ready in about 30 minutes pairs beef sirloin, large yellow onion, cremini mushrooms for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 520 calories and feeds 2, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 12 oz beef sirloin
• 1 large yellow onion
• 8 oz cremini mushrooms
• 2 tbsp unsalted butter
• 3 cloves garlic
• 1/4 cup heavy cream
• 1/2 tsp sea salt
• 1/4 tsp black pepper

Instructions

1. Step 1: Slice beef sirloin against the grain into 1/4-inch thick strips, then season with 1/4 tsp salt and 1/8 tsp pepper. Heat 1 tbsp butter in a large skillet over medium-high heat until shimmering.
2. Step 2: Add beef in a single layer, searing for 2 minutes per side until browned but not cooked through; transfer to a plate.
3. Step 3: Add remaining 1 tbsp butter to skillet, then slice onion into thin half-moons and mushrooms into 1/2-inch pieces. Cook over medium heat for 10 minutes until onions are golden and mushrooms release liquid.
4. Step 4: Add minced garlic and cook for 30 seconds until fragrant, then return beef to skillet. Stir in heavy cream and remaining salt and pepper, simmering for 3 minutes until sauce thickens and coats the beef.