This quiche is easy to make and really tasty. You can use any kind of cheese combination. Grate the cheese on the large holes of the grater. This is a great way to use up bits and pieces of left over cheese. I usually make this after a party, when I have lots of kinds of left over cheese that may not get used up otherwise. I have even used Parmesan and feta mixed with other cheeses and it always tastes great. Try whisking in 1 1/2 tsp of dijon mustard with the half and half or milk for a little more flavor. I have subsequently made this with 1 bunch of well sauteed, chopped, swiss chard and 1/2 onion, finely diced. I sauteed them in 3 tbsp butter for 15 minutes over med heat, and used 1 1/2 c. of the cooked chard and onion instead of the spinach. Everything else remains the same. It was really, really good.