Preheat oven to 350°. Spread green chiles in a greased 11x7-in baking dish; sprinkle with olives, onion and cheese. In a large bowl, whisk eggs, biscuit mix, milk and pepper until blended. Stir in cottage cheese; pour over top.
Bake, uncovered, until golden brown, puffed and a knife inserted in the center comes out clean, 45-50 minutes. Let stand 5-10 minutes before serving. If desired, serve with salsa and sour cream.
To Make Ahead: Refrigerate unbaked souffle, covered, several hours or overnight. To use, preheat oven to 350°. Remove souffle from refrigerator while oven heats. Bake, as directed, increasing time as necessary until golden, puffed and a knife inserted in the center comes out clean. Let stand 5-10 minutes before serving.