Place the first 5 ingredients in a wide pot set over medium heat. Cook and stir until the meat is crumbly and cooked, about 10 minutes. Drain the excess liquid from the pot. Add the tomatoes, salsa, stock, chili powder, cumin, oregano and pepper. Bring to a gentle simmer, cook 10 minutes, and then remove from the heat.
Place refried beans in a small pot with 2 Tbsp. water and set over medium. Heat beans until just warm and more fluid, and then remove from the heat.
Preheat your oven to 350°F. Spoon and spread a quarter of the turkey mixture into the bottom of a 9 x 13 inch pan. Top sauce with 2 tortillas, slightly overlapping them.
Top those tortillas with a third of the remaining turkey mixture. Using a small spoon, drop a third of the sour cream, and a third of refried beans, in small dollops at various spots around the turkey mixture. Now sprinkle on ¾ cup of cheese.
Top the cheese with 2 more tortillas. Top those tortillas with half of the remaining turkey mixture, sour cream and refried beans. Sprinkle on another ¾ cup of cheese.
Top that cheese with 2 more tortillas. Spread on the remaining turkey mixture, and then top with remaining sour cream and refried beans. Sprinkle on another ¾ cup of cheese.
Set on the last 2 tortillas and top with the remaining ¾ cup of cheese. Tent casserole with aluminum foil and bake 40 minutes. Uncover and bake 10 minutes more, until the sauce is bubbly and the top of the lasagna is light golden brown.
Rest the lasagna 10 minutes. If desired, before slicing and serving, sprinkle the top of lasagna with cilantro or green onion.
Note: 3 cups of grated cheese equals about 300 grams. If desired, you could use the bagged, shredded cheese we sell in this recipe.