Place spinach in a heat-proof bowl. Cover with boiling water and allow to stand for a few minutes while the spinach defrosts (this is cooking your spinach as well).
Drain spinach and squeeze out the excess moisture. Place back in the bowl.
Stir in the crushed garlic, parmesan and oil.
Taste and season with a little salt, if needed (It may not because of the Parmesan)
If using the plus ingredient, finely chop the nuts and stir through.