Caramelized Onion Phyllo Tarts without tart vinegar

2 tablespoons butter 2 large sweet onions (sliced or diced thinly) 3/4 cup hot water 1 tablespoon beef bouillon (or 3 cubes) 2 (2 ounce) packages frozen[...]

2 tablespoons olive oil 2 medium onions , sliced 2 red apples , cut into small pieces (such as Braeburn or Gala) kosher salt and black pepper 2 sheets frozen[...]