{Erin: I also left out the cardamon pods also (first, b/c I couldn't find pods, second b/c grounded cardamon was 12 bucks in a little spice jar). }

Garam Masala is a mixture of various spices. Ground cardamon, cloves, cumin, black pepper are included in almost ALL brands of Garam Masala (check the ingredients). I would have added a teaspoon of garam masala to the marinade albeit heating the individual spices in a little butter helps to bring out all the wonderful flavours to the maximum.