Step 1

Prepare: Preheat oven to 375 F. Set aside 8x8 inch baking dish (Note 6).

Step 2

Cook Beef & Mushrooms: Add beef and salt to high-sided pan (Note over high heat. Crumbling beef with stiff utensil, cook until browned and releasing liquid, a few minutes. Keeping everything in pan, add mushrooms and garlic. Cook until mushrooms are shrunken and most of released liquid has evaporated, stirring occasionally, 6 to 8 minutes. The only remaining liquid should be beef grease.

Step 3

Assemble Casserole (Note 8): Transfer beef-mushroom-garlic mixture to baking dish (Note 9). Stir in goat cheese and 2/3 of swiss cheese until well-mixed with beef and mushrooms; goat cheese should melt quickly, nicely coating other ingredients. Evenly sprinkle scallions on top, then distribute remaining 1/3 of swiss cheese over them. Arrange surface of casserole so it's flat and even.

Step 4

Bake & Serve: Transfer baking dish to oven. Bake uncovered at 375 F until casserole is very hot, bubbling up sides, and cheese is completely melted, about 15 minutes. Let casserole cool at room temperature for 5 minutes, then cut into 4 equal portions. Serve hot (Note 10), and store any leftovers (Note 11).