Line a stainless steel skillet with foil (or use a disposable foil pan). Heat over high heat.
Add the tomatillos and jalepeno to the pan and cook until charred and slightly softened, about 10 minutes -- tomatillos will be softer than jalapeño.
Char the poblano pepper on all sides, either in the same skillet lined with foil -- or if you have a gas stove top, rest the chile directly over the flame, until the skin blisters and chars.
Turn the pepper occasionally until blackened. Remove from heat and let cool until you can handle it without burning your fingers. Transfer the peppers to a bowl sealed in plastic wrap or a brown paper lunch bag, sealed. Let the pepper steam and cool for 10 minutes.
Slough off the blackened portion of the peppers. Slice the peppers in half, lengthwise and remove the seeds and stem. Transfer to the blender with tomatillos and jalapeños.
In the skillet, heat one tablespoon of canola oil over medium high heat. Add the onion and garlic and saute until softened and translucent, 3-4 minutes.
Stir in the cumin, salt and pepper and cook for one minute longer. Transfer to the blender with the peppers and pulse to combine.
ASSEMBLING THE GREEN ENCHILADA SAUCE:
Add the lime juice and cilantro and process until smooth. If the sauce is too thick, add the water two tablespoons at a time and pulse to blend. Add more water if necessary.
Adjust seasonings to your taste. Keep refrigerated until ready to use.
Notes
Store the salsa in a resealable container or jar in the refrigerator for 5-7 days.