1.In a small saucepan, melt the butter over medium low heat. When the butter is completely melted, add the flour.
2.Stir to combine the butter and flour. The butter and flour will fuse and swell. Do not stop stirring because the roux will easily burn. After 20-30 minutes, the roux will turn to light brown color.
3.Add the curry powder, garam masala and cayenne pepper. Cook and stir for 30 seconds and remove from the heat. If you don't use it immediately, let it cool in an airtight container with lid and store in refrigerator for a month or freezer for 3-4 months. Use with 4 cups of liquid, makes 1 pot of curry.