Melt the butter in the oil in a large dutch oven for 2 minutes over medium heat. Place onions, garlic, celery, and jalapenos in the food processor fitted with a steel blade; pulse until chopped coarsely. (Alternately chop by hand.) Add vegetables to the pot and season with one teaspoon EACH kosher salt, fresh ground pepper, dried oregano, ground cumin, and ground coriander. Stir and cook for about 5 minutes or until softening. Pour in tequila; simmer for a few more minutes until reduced by half. Add in the chicken and parsley along with the reserved 2 teaspoons each dried oregano, ground cumin, and ground coriander. Cook, stirring regularly, until chicken is done through and no pink remains—another 10-12 minutes.