Cactus pads, or nopales, have been consumed for generations. Studies suggest that nopales may control blood sugar levels in some people. I think they have a flavor similar to green beans. They are available at most Latino markets and come cleaned to make it much easier to prepare at home.
For the stuffing: In a medium saute pan on medium heat, add the olive oil, cactus, onions, garlic and salt and allow to sweat for about 5 minutes. Continue to cook until the onions are fully cooked, 5 to 7 minutes longer; set aside.
For the chicken: Place about 2 tablespoons of the cactus mixture on one side of each chicken breast. If you have remaining stuffing, reserve it for garnish. Top with the cheese. Using a brush, coat the edges of the chicken breasts with the egg and close
Preheat the oven to 350 degrees F.
Heat a saute pan over medium-high heat and add the canola oil. Season the chicken breasts with the salt and pepper. Carefully place each stuffed breast in the hot pan. Sear each side so that there is a nice crust, about 3 minutes. Place the chicken on a sheet pan, place in the oven and bake for about 25 minutes or until the internal temperature is 265 degrees F.
For the sauce: Reduce the heat to low under the saute pan that was used for the chicken. Toast the cumin, coriander and paprika in the pan a minute or two; do not burn the spices. Very carefully add the tequila; it may ignite, but not for too long. Add the lime zest and juice. Add the chicken stock, salt and pepper, lower the heat and allow to reduce, about 10 minutes.
Place the chicken in a serving dish, cover with the sauce and garnish with any remaining cactus stuffing and chopped fresh parsley.