To prepare the masa: In a bowl pulverize achiote with your fingers. Dissolve achiote in orange juice and grape seed oil; add marjoram, mixing just to incorporate ingredients.
Add 1 ½ cups of chicken broth and knead dough until soft and pulls away from sides of bowl. Masa is forgiving, if too wet add more masa harina and knead well. If too dry knead in more liquid.
Form into a ball, cover with a dishtowel and let rest while preparing tinga.
To prepare the Tinga: Melt butter and sauté onion for one minute, then add nopal, garlic, oregano, and chile chipotle and continue to cook for another minute.
Add tomato, salt, pepper, ½ cup chicken broth and cook on medium high heat for 10 minutes.
Cool and reserve.
To prepare Quesadilla: Roll prepared masa into golf ball size pieces. Flatten with a tortilla press between circles of plastic wrap (cut from sandwich or freezer bags). Then lift off tortilla. Flip tortilla onto a work surface and remove other piece of plastic film.
Place about one heaping tablespoon of tinga de nopal in center of each tortilla. Fold in half pinching edges to seal. Fry in hot vegetable oil for about 5 minutes until golden brown.
Drain on paper towel.
To serve, drizzle crema over quesadillas, top with grated cheese and avocado slices. Accompany with your favorite salsa.