Using a mandoline, cut potatoes into waffle fries. Add to a large bowl and fill with enough cold water to cover the fries. Refrigerate for about 1 hour.
While your potatoes are chilling, melt butter in a medium saucepan over medium-high heat. Stir in flour until the mixture is smooth. Stir in garlic and cook until soft, approximately 2 minutes. Add stock ketchup, Worcestershire, salt, and pepper. Bring the mixture to a boil, stirring occasionally, until thickened, approximately 6 minutes. Cover and keep warm on low heat.
Pour enough oil into a dutch oven to be 3″ deep. Heat over medium heat until the temperature reaches 325 degrees. Drain potatoes and dry completely with paper towels. Fry the potatoes, working in small batches, until tender and just crisp. Remove to a paper towel lined plate to drain. Cool for 20 minutes.
Increase heat to medium-high and allow oil to heat to reach 375 degrees. Fry potatoes in the same small batches, until golden brown, approximately 2 minutes. Remove to fresh paper towel lined plate and sprinkle with salt (add a dash of cayenne to the salt to spice things up!).
Add fries to a large skillet or serving bowl and pour gravy on top. Sprinkle over bacon, Sgt Pepper cheese chunks and garnish with fresh chopped parsley.