Preheat the oven to 250°F. You can also go ahead and line 2 rimmed baking pans with parchment paper to reduce sticking. Lining the pans is optional, but it sure makes cleanup easier.

Place all of the cereals and nuts in a large mixing bowl roomy enough that it can hold everything with plenty of space for mixing. Use your hands to mix it well. Hands work better than a spoon to keep the cereal from breaking up.

In another small to medium-sized bowl, whisk together the Worcestershire sauce, lemon juice, veggie broth, garlic powder, onion powder, nutritional yeast (if using) and season salt. Sometimes, the nutritional yeast flakes can make it too thick. Just add a little more vegetable broth or water. I have found that it's actually good to make a little thicker than 'sauce' so it seasons and coats the mix even better, but you don't want it so thick that it won't incorporate well.

Pour the wet seasoning mixture over the cereal and nuts in the large bowl and gently toss to coat each piece evenly. Don’t worry if it’s not completely even because you are going to be stirring throughout the cooking process. I like to use my hands to mix because it helps the cereal not to break up as much.

Pour the mix onto the lined baking sheets in a single layer. You want the pans to have rims because they will be pretty full.

Bake in the oven for 1 hour, stirring every 15 minutes until lightly golden brown. Allow it to cool for about 10 minutes before serving. It will crisp up even more as it cools.