Heat a non-stick pan over high heat. Once the pan is smokey hot, remove from heat. Add the pine nuts and shake the pan until they get a golden color all around. Remove from pan and set aside to cool.NOTE: Shake the pan every 2-3 seconds as they burn easily.
In same pan, add a good splash of olive oil and caramelize the onion over medium heat.
Add the rice, parsley, dill and lemon zest. Stir using a wooden spatula. Cover the rice slightly with water.
Once the rice absorbs all the water, remove from heat. Mix in the pine nuts. Season with salt and pepper.
In a strainer drain the vine leaves from their brine.
Cover the bottom of a medium-sized cooking pot with a few vine leaves.
Lay open (one at a time) the vine leaves (bottom-sides up) on your working surface.
Add 1 generous teaspoon of filling in the center. Fold upwards once. Then fold its right and left side inwards. Then start rolling upwards.
Keep doing that, until you roll all the vine leaves (do not fold them very tight, since the rice will get bigger in size and they will pop open if you do)
Add the stuffed vine leaves one by one in the pot, creating a cross-like shape. Then fill the sides of the cross (this way they'll keep nice and tightly together).
When you have rolled all leaves, add a plate on top (to keep them down while simmering) Cover slightly with water and add the olive oil.
Cook for 25-30 minutes over medium-low heat half-covered with the pot's lid.
Whisk cornflour with lemon juice in a bowl and add to the pot . Shake the pot for the mixture to spread evenly.
Simmer for 2-3 more minutes. Remove from heat and set aside.
Once they cool a bit, remove the plate and serve.