Dry roast the pumpkin seeds, apart from 1 tbsp for decoration, for a few minutes in a frying pan.
Grind them up in the blender. Set aside in a bowl. You'll need the blender again.
In the same frying pan, add the oil and gently fry the onion. Add the garlic.
Add the spices and the already charred and chopped chilli
Add the tomatillos, simmer for a few minutes then add the vegetable stock.
Then blend this mixture until liquid.
Put this mixture back in the frying pan and cook for a few minutes
Add the ground pumpkin seeds which will absorb the liquid until you have a thick sauce. Keep tasting and add salt.
Finally add a big squeeze of lime and fresh coriander leaves. Decorate with the whole pumpkin seeds.
Use as a sauce for bean stew or for tamales or whatever. It will keep in the fridge or freezer