According to Wikipedia, garam masala is Hindi for "hot spices". "Hot" actually refers to the intensity of the spices, not the heat level. Garam masala recipes vary by region, but typically contain black and white peppercorns, cloves, cinnamon, black and white cumin seeds, and black, brown, and green cardamom pods.
You can find garam masala in most Asian stores, but it is also easy to make your own. My version is a simplified version of the Garam Masala recipe found in Extending the Table: A World Community Cookbook by Joetta Handrich Schlabach.
Mix one tablespoon ground cardamon, 5 teaspoons coriander, 1 teaspoon cumin, 1/4 teaspoon cloves, 2 tablespoons black pepper. Toast lightly in heavy frying pan, stirring occasionally.
And that's all there is to it! My apartment smelled like an Indian restaurant for hours; it was a pleasant smell. This recipe makes about 1/3 cup--plenty for any Indian recipe you can think of.
So what are its benefits? "Garam masala contains several micronutrients," Wikipedia reports. "Ten grams have about 75 milligrams of calcium, 3 milligrams of iron, 150 milligrams of potassium, and 0.3 milligrams of zinc." Ten grams of garam masala equals 2 teaspoons, according to convertunits.com.
Now that you know how to make your own Garam Masala, here's a recipe that calls for it. Again, it's a simplified, microwavable version of a recipe from Extending the Table.
Egg Curry, or as it's called in India, Anda Kari. Combine 2 chopped large onions, 2 cloves garlic and 1 tablespoon oil and cook on high for 3 minutes. Add 1 teaspoon ground tumeric, 1 teaspoon ground ginger, 1 teaspoon ground cumin, 1 teaspoon paprika, 1 1/2 teaspoons ground coriander, 1/2 teaspoon salt, 1/4 teaspoon ground red pepper, 1 teaspoon garam masala, and 1 1/2 cups tomatoes. Cook on high 6 to 8 minutes. Add 4 to 6 hard-boiled eggs, cut in half, cook on high 3 to 5 minutes. Serves 4.