5 Tbs butter, divided
2 lg onions, thinly sliced
salt
1 cup dry white wine, divided
6 thyme sprigs
1 cup heavy cream
3 cloves garlic, smashed
4 (10oz) bags baby spinach
salt
2 large pinches ground nutmeg
1 cup breadcrumbs (homemade soft recommended)
1 1/2 c grated cheddar cheese (I plan on using a mix of white cheeses)
1 Tbs fresh thyme finely chopped


In a large skillet over medium heat, melt 3 Tbs butter. Add onions and 1 1/2 tsp salt. Saute onions until they begin to turn translucent. Add 1/2 cup wine and thyme sprigs, reduce heat to medium low, cover and cook 30 minutes, stirring occasionally. Increase heat to medium, uncover and add remaining 1/2 cup wine. Cook for 20 to 30 minutes until onions begin to brown. Listen for the sizzle, then stir more frequently so they don't burn. Onions are done when they have a rich golden color and jammy consistency. Remove thyme sprigs and set onions aside.

Meanwhile, prehat the oven to 375 degrees.

Heat cream with garlic just until it begins to simmer. Turn off heat and set aside.

Wash two bags spinach leaves in a large colander but don't dry them. Put the leaves in a wide soup pot with water still clinging to the leaves. Add 1/4 tsp salt and cook over high heat, turning occasionally untl the leaves wilt and turn bright green, about 4 to 6 minutes. Return the spinach to the colander and, using a wooden spoon, squeeze out the excess liquid. Finely chop the spinach. Repeat with the remaining two bags.

In a large skillet or pot, melt the remaining 2 Tbs butter. Over high heat, add the spinach and cook until the excess water in the spinach evaporates. Pour cream through a strainer directly into pan and simmer until it thickens slightly. Add nutmeg and stir in carmelized onions.

Transfer to a 2-quart casserole or gratin dish.

Combine breadcrumbs, cheese, and thyme. Spread evenly over spinach. Bake for 25 minutes or until top is golden.