Into a saute pan, add olive oil and onion. Saute until translucent, add in fresh spinach, season with salt and pepper and wilt down for a few minutes. Set aside to cool.
Into a bowl, add ricotta, grated parmigiano, salt, pepper, mozzarella, diced ham, spinach. Taste for seasoning before adding the egg. Add in 1 egg and stir to combine.
Boil the shells according to the package instructions. Drain and then run under cold water.
Using a small spoon, fill each shell to the top.
Into a large baking dish, add sauce and béchamel to the bottom. **See video for visual** Reserve some sauce for plating.
Than place the stuffed shells on top. Add more sauce and béchamel on top. Cover with aluminum foil and bake at 400℉ for about 45 mins or until bubbling.