Prep your base. Chop the lettuce and set it in bowls. If using cauliflower rice, sauté it in a little oil with salt and pepper until tender, then divide among bowls.

Make the sauce. In a small bowl, whisk mayo, heavy cream, Dijon, a splash of Worcestershire, a pinch of salt, and pepper. Adjust to taste. It should be creamy, slightly tangy, and pourable.

Sauté the mushrooms. Heat a large skillet over medium-high. Add 1 tbsp butter and 1 tbsp oil. Add mushrooms in a single layer with a pinch of salt. Cook, undisturbed, 3–4 minutes to brown, then stir and cook 2–3 more minutes until tender.

Add onions and garlic. Push mushrooms to the side. Add remaining butter and the sliced onion. Cook 3–4 minutes until soft and golden. Stir in garlic for 30 seconds until fragrant.

Deglaze lightly. Pour in the beef broth and 1 tsp Worcestershire. Scrape up the browned bits. Let it reduce for a minute until saucy, not watery. Transfer the mushroom-onion mixture to a bowl and keep warm.

Cook the beef. In the same skillet, add ground beef. Season with salt, pepper, and optional onion/garlic powder. Break it up and cook over medium-high until browned with crispy edges, about 6–8 minutes. Don’t over-stir; let it sear.

Melt the cheese. Reduce heat to low. Return the mushrooms and onions to the skillet, toss with the beef, and top with Swiss. Cover for 1–2 minutes until melted and glossy.

Assemble the bowls. Add the beef-mushroom-Swiss mixture over your greens or cauliflower rice. Spoon the creamy sauce over the top. Finish with chopped parsley or chives and a grind of black pepper.

Taste and tweak. Add a pinch of salt, an extra drizzle of Worcestershire, or a little Dijon in the sauce if you want more brightness.