To roast Poblanos: Place poblanos under the broiler for 10 minutes or so, turning as the skin blisters. It should be blistered on all sides.
Remove the peppers to a shallow bowl and cover with plastic wrap. Allow to sit for 5-8 minutes.
At this point the skin should come off easily. Remove the stem and seeds and chop.
Put the quinoa, bell peppers, poblano, onion, corn and black beans in a large mixing bowl. Toss to combine.
Add the avocado and cilantro to the bowl and toss gently to combine.
Pour the canola oil into a small fry pan. Add the garlic and the cumin seeds and heat over low heat until the garlic stats to sizzle. Remove from heat (do not let the garlic brown) and set aside to cool before adding to the dressing jar.
Combine all of the dressing ingredients in a jar with a lid. Cover tightly and shake until ingredients emulsify.
Pour the dressing over the ingredients in the bowl and toss gently to combine.
Cover the salad and chill for several hours. Remove from refrigerator 15 minutes before serving.
This serves 4 as a main dish and 6 or more as a side dish.