Melt 2 tablespoons butter in a frypan over medium heat and saute the onions and mushrooms until tender. Mix in the wine and continue cooking about 5 minutes, until heated through.
In a large bowl mix the Ranch dressing, garlic powder, oregano, Cajun seasoning and cayenne pepper. Stir the frypan mixture into the bowl. Mix in remaining 2 tablespoons butter, eggs and salada crumbs.
Dip the chicken breasts in the Ranch dressing mixture to coat. Arrange chicken in a medium baking dish. Cover with the remaining dressing mixture.
Bake 1 hour in the preheated oven or until chicken is no longer pink and juices run clear.