1-First, melt the butter in a large skillet over medium-low heat. This step infuses the dish with a rich base, so stir frequently to avoid burning.

2-Add the finely chopped shallots and cook until soft and translucent, about 4 minutes, building that essential savory depth.

3-Next, add the finely chopped garlic and cook, stirring constantly, for 1 minute more without browning to keep the flavors fresh.

4-Then, pour in the heavy cream, salt, pepper, and nutmeg, and bring to a gentle boil. The key is to cook uncovered, stirring occasionally, until the cream thickens enough to coat a wooden spoon, which takes about 10 minutes.

5-Once thickened, stir in the cheese until it melts smoothly into the sauce.

6-Add the spinach whether thawed frozen or freshly steamed and drained and mix until evenly combined.

7-Taste and adjust seasoning if needed, and if it seems watery, cook on medium-low heat until excess liquid evaporates.

8-Finally, serve warm, perhaps alongside your favorite main course for a complete meal.