Slice the cherry tomatoes in half, place in a baking pan, add 2 tablespoons olive oil and roast at 350 degrees for about 20 minutes, until tomatoes are bursting. Set aside.
Place poblanos under the broiler and turn continuously, until the poblanos are charred. Set aside.
In a skillet over medium heat, saute onion and remaining olive oil; when the onion is transparent add the quinoa and beans. Mix carefully. Remove from heat, add seeds, lemon zest, salt, and the roasted tomatoes. Set aside.
Carefully open the chiles and rinse well inside so that all the seeds are removed. (Devein the poblano chili peppers with a fruit knife if you do not want them to be spicy.) Stuff them carefully with the mixture of quinoa and beans. Serve with avocado pieces and finish with chopped cilantro.