If you haven’t made the chimichurri yet, make that first. It tastes better as it sits, so make it first and let it sit while you prepare the rest of the ingredients. This will make a good amount of chimichurri - there will be some leftover. Store it in the fridge and use it on meats, salads, vegetables, etc.
Preheat the oven to 450 degrees. Place the fries on a baking sheet. Roast at 450 degrees for 20 to 25 minutes or until super crispy and crunchy.
While the fries are cooking, make the bacon. Place the bacon in a skillet over medium-low heat. Sprinkle all over with the chipotle chili powder. Cook, stirring occasionally, until crispy and the fat is rendered. Remove the bacon with a slotted spoon and place it on a paper towel to drain excess fat.
Make the cheese sauce! Heat the butter in a saucepan over medium heat. Whisk in the flour to create a roux - cook it for 2 to 3 minutes until it’s golden, fragrant and nutty. Slowly stream in the milk while whisking the entire time. Whisk and stir until the milk thickens, about 5 minutes. Turn the heat to low and stir in the cheese 1 handful at a time, stirring until melted. Taste and season with salt and pepper if needed.
When the fries are done, drizzle them all over with the cheese sauce. Top with a drizzle of chimichurri. Add the chipotle bacon. Serve!