Instructions

• Place a rack in the lower third of the oven and preheat to 450°F. Drizzle a large rimmed baking sheet with 1 1/2 tablespoons extra-virgin olive oil and use a brush or paper towel to coat the pan evenly.
• Scrub the 2 medium/larger russet potatoes (about 1 1/4 pounds); peel if you prefer to remove the skins. Cut the potatoes into 1/4-inch-wide sticks.
• Put the cut potatoes in a large bowl and cover with very hot water so the potatoes are submerged by about 1 inch. Let sit for 10 minutes to remove excess surface starch.
• Drain the potatoes in a colander and pat them completely dry with a clean kitchen towel or paper towels.
• Rinse and dry the bowl you used for soaking, then return the dried potatoes to the bowl. Drizzle with the remaining 1 1/2 tablespoons extra-virgin olive oil. Sprinkle with 1 tablespoon Cajun seasoning, 1 teaspoon garlic powder, 1/2 teaspoon dill weed, and 1/4 teaspoon onion powder. Toss thoroughly so the oil and spices coat the fries evenly.
• Spread the seasoned potatoes in a single layer on the oiled baking sheet, making sure they are not piled on top of each other so they can crisp.
• Roast on the lower third of the oven for 15 to 20 minutes, until the undersides are turning golden.
• Remove the pan from the oven. Use a large spatula to gently loosen the fries from the pan and flip them over in large sections so they brown evenly. Spread them back into a single layer.
• Return the pan to the oven and continue roasting until the fries are golden and as crisp as you like, about 5 to 10 more minutes (total roast time may be up to ~30 minutes for very crispy fries).
• While the fries finish roasting, make the cheese sauce: In a wide saucepan over medium heat, melt 2 tablespoons unsalted butter. Add 1 1/2 tablespoons all-purpose flour and whisk constantly for 1 full minute to cook the flour.
• Slowly add 1 cup milk, whisking constantly as you pour so the mixture stays smooth. Bring the mixture to a gentle boil and continue stirring for 1 minute; it should thicken and reduce slightly.
• Remove the saucepan from the heat and slowly stir in 1 cup (4 ounces) freshly grated sharp cheddar cheese a little at a time, stirring until the sauce is smooth and fully combined.
• Transfer the fries to a serving plate (or serve directly from the sheet pan). Drizzle with the cheese sauce and ranch dressing, if desired. Sprinkle with chopped chives or green onions, if desired, and serve immediately.