Preheat oven to 450 degrees.
In a saucepan, melt 2 T. butter and add cream.
On medium heat, simmer butter and cream until bubbly and slightly thickened about 5 minutes.
Gradually add cheese, while whisking.
Cook on low until thick.
In a separate skillet, saute onions in 1 T. butter until soft, about 3 minutes.
Add chopped spinach and cook until wilted.
Add spinach and onions to cheese sauce.
Divide evenly into four ramekins and place ramekins on baking sheet or square dish for easy handling in the oven.
Bake for 10 minutes.
Carefully add an egg to the center of each hot ramekin and bake for an additional 6-8 mins. The white should no longer be clear and should still jiggle a bit.
Remove from oven and let sit for 10 minutes. The egg will continue to cook the longer it sits.
Garnish with fresh herbs and serve immediately.