Heat cooking oil in a hot pan and seal the chicken for about 3 minutes each side, then place on a baking tray. Set aside.
Place the tomatoes in a blender with La Costena chipotles and puree until a smooth consistency. Set aside.
In a hot pan, sauté the onions and the garlic in oil. Once translucent, add the pureed tomatoes and the bouquet garni then cook for 10 minutes over medium heat to create the sauce.
Once complete, pour the sauce into the baking tray with the chicken. Cover the tray with baking paper and foil then place it in the oven (at 180 °C) for 90 minutes. Remove from the oven and shred the chicken in the cooking juices while still hot. Set aside.
Heat cooking oil in a frying pan, enough to cover 1cm to 2cm from the bottom. Cooking individually, place each tortilla into the oil and fry until crispy and golden, ensuring the tortilla stays submerged in the oil throughout cooking. Once cooked, place on paper towel to drain excess oil.
Mix the sour cream and thickened cream together until combined and runny.
Place a layer of refried beans over each tortilla then top with chicken (drain off any excess liquid), shredded lettuce, drizzle of the cream and sliced avocado. Top with your favourite La Costena Salsa.