Start by washing and peeling the large russet potatoes. Cut them into thin fries, about ¼ inch thick, to ensure they cook evenly. Soak the cut fries in cold water for 30 minutes to remove excess starch, then drain and pat them dry.

In a large mixing bowl, add the dried fries and drizzle them with olive oil. Sprinkle in garlic powder, onion powder, smoked paprika, salt, and black pepper to taste. Toss together until the fries are evenly coated.

Preheat your oven to 425°F (220°C). Spread the seasoned fries in a single layer on a baking sheet lined with parchment paper. Bake for 25-30 minutes, flipping halfway through for even cooking, until golden-brown and crispy.

While your fries are cooking, heat a skillet over medium heat and add a drizzle of olive oil. Toss in diced red onions and bell peppers, cooking until soft and caramelized, about 6-8 minutes.

Transfer the baked fries to an oven-safe dish. Generously sprinkle shredded cheddar and mozzarella cheese on top. Return to the oven for an additional 5 minutes, or until the cheese is gooey and bubbling.

Layer the sautéed vegetables on top of the cheesy fries. Sprinkle jalapeños, chili flakes, and dried oregano if desired.

In a small bowl, combine sour cream (or Greek yogurt), mayonnaise, lemon juice, garlic powder, and smoked paprika. Whisk until smooth and creamy. Drizzle generously over the assembled dish.

Garnish your Ultimate Dirty Fries with freshly chopped parsley or cilantro. Serve hot as a delightful snack or comfort food centerpiece.