Bring 6 quarts of water to a full boil. Salt the water.
Add the pasta all at once. Stir gently to submerge. Reduce the heat slightly to prevent boil-over, and boil pasta according to the packaging until al dente.
When the pasta is done, remove and reserve ½ cup of starchy water the pasta cooked in.
Drain and return the pasta to the pot you cooked it in. Turn the heat up to medium-high.
Add the reserved liquid, spinach, garlic, lemon juice, olive oil, salt, pepper and nutmeg. Stir gently but thoroughly until the spinach is wilted and the sauce has reduced and emulsified, about 3 minutes.
Remove the pot from the heat and fold in the grated cheese and the minced herbs—correct seasonings.
Plate and top each serving with some toasted pine nuts.