Heat a large saute pan with a little oil and saute the onion, garlic, and the roasted poblano pepper for 5 minutes, until the onions have become translucent. Then, add the squash blossoms and deglaze with chicken stock. Add the epazote, and cook for another 5 minutes until squash blossoms have wilted. Season with salt and pepper, and set aside to cool.
To compose the quesadilla lay the 2 of the tortillas on a flat surface. Distribute the cheese equally on both tortillas. Then, spread 1/2 of the squash blossom filling over the cheese. Cover with the other tortilla, place on heated griddle on nonstick saute pan with a little oil, and cook for 3 minutes on each side. When nice and golden brown on each side and cheese has melted, remove and cut into quarters.