In a large bowl, combine the grated cheddar cheese, cream cheese, ranch seasoning, sour cream, Dijon mustard, and green onions. Mix with a spatula or wooden spoon until well incorporated.

For a Cold Dip: Cover the bowl with plastic wrap and chill in the refrigerator for at least two hours or overnight for the best flavor.

For a Warm Dip: Transfer the mixture to a shallow baking dish and bake at 350°F for 15-18 minutes or until the cheese is melted and the top turns golden.

Finally, garnish with additional diced green onions and serve with pretzels.