Turn your oven to 250˚F.
In a roasting pan, combine the shredded wheat, Chex, Fritos, pretzels, and nuts. Toss to combine.
combine the remaining ingredients in a sauce pan, and bring to a simmer. When the butter has melted, stir the pot well, then drizzle the mixture over the cereals, tossing as you do, and stopping to stir the pot frequently so the onion and garlic powders don't settle on the bottom. The idea is to get everything uniformly coated with the mixture.
Put the roasting pan in the oven and cook for 90 minutes, stirring and tossing thoroughly every 15 minutes or so.
Remove form the oven and allow to cool completely. Store in an air tight container.