Preheat oven to 350°.
Remove the stems from all 30 of the mushrooms. Set mushroom caps aside in a 9×13 baking dish. Finely chop 10 of the stems. You may discard the rest or save them for another time.
Cook Quinoa in a saucepan by combining 1 cup Quinoa with 2 cups water, bring to a boil, and cover until the Quinoa has absorbed all of the water (about 10-15 minutes). Remove from heat.
In a skillet over medium heat, sauté chopped mushroom stems, onion, spinach, cilantro, olive oil, and about 1/4 tsp Sea Salt (or to taste). Grind in some fresh black pepper and cook until onions are translucent. Remove from heat.
Dice all of your lovely peppers. Be careful with the jalapeño; remember that the more seeds you keep, the spicier the mix will be!
In a medium bowl, combine all ingredients (except mushroom caps). Mix thoroughly with a spoon.
Using a tablespoon, fill each mushroom cap with stuffing. Stuff them as full as possible. Any leftovers can be eaten as a side dish!
Place in the oven for 15 minutes. Remove them from the oven and allow them to cool for about 10 minutes before serving.