Lightly grease six 120 ml / 4 oz ramekins or dariole molds with the neutral oil. Set them aside.
In a 2-quart / 1.9L saucepan, whisk the cornstarch into 120 ml of the almond milk until fully dissolved with no lumps.
Add the remaining almond milk, sugar, salt, lemon zest strip, and cinnamon stick to the saucepan. Whisk to combine.
Set over medium heat and cook, whisking constantly, for 8 to 10 minutes, until the mixture thickens enough to coat the back of a spoon and holds a trail when you drag a finger through it. It should look glossy, not lumpy. Strain through a fine-mesh sieve first if any lumps have formed.
Remove from heat and fish out the lemon zest strip and cinnamon stick.
Divide the pudding among the prepared molds. Tap each one gently on the counter to release air bubbles.
Cool at room temperature for 20 minutes, then cover and refrigerate for at least 4 hours, or overnight, until fully set and firm to the touch.
To unmold, run a thin knife around the edge of each pudding, dip the base in warm water for about 5 seconds, then invert onto a plate.
Dust with ground cinnamon, scatter the chopped pistachios, and drizzle with honey if using. Serve chilled.