In a skillet, sauté the onions in the butter until soft. Add the mushrooms and the spinach, plus 1/4 cup water.
When the liquid in the pan is gone, turn the contents onto a cutting board and chop.
Return the pan contents to the skillet, add the cream, and lower the heat. Bring to a simmer and cook for about three minutes, stirring lightly. Turn off the heat.
Cut the cream cheese into pieces and stir into the pan contents. Add salt, pepper, and jalapeno pepper sauce to taste.
