Drain the scallops, pat them as dry as you can with paper towels and set them aside to dry out further.
Melt 1 Tbsp butter and 2 Tbsp oil in a large skillet over medium heat. Add the chopped onions to the skillet and saute for about 5 min. Or until light brown and caramelized. Once onions are caramelized, add the minced garlic for about 30 seconds (do not burn)
Add wine to deglaze the skillet and cook over med-high for a minute or two to blend. Add the spinach, cream, salt and pepper and nutmeg to the skillet and cook over med-low heat for about 5 minutes or until thoroughly blended. Taste and add more seasoning if needed. Fold in the cheese and remove from heat.
Pat the scallops dry again with paper towels, getting them as dry as you can to take a good sear. Season them with salt and pepper and ground fennel (sometimes I use smoked paprika).
In a clean, large skillet,heat 2 Tbsp of oil over high heat until shimmering hot. Place half of the scallops in the skillet, starting with the 6:00 position and moving clockwise around the skillet. Cook them, undisturbed, until browned on the bottom (resist the temptation to pick them up and look or move them, they will come away from the pan easily once they are seared). Flip them (after about 2-3 minutes and continue to cook about 1 minute longer. Repeat with remaining scallops, adding (and heating)more oil to the skillet before searing if needed.
Serve over the spinach and enjoy.