Start by pouring about 1/4 inch of oil in a cast iron skillet and heat it over a medium-high flame on the stovetop. Again, you want the oil to reach right about 325ºF before adding the potatoes.
While you're waiting on your cast iron skillet to heat up, wash the potatoes and use a small paring knife to cut out any bad spots.
Next, cut use a large chef's knife to cut your washed potatoes lengthwise into 1/4" wide strips.
Then cut each strip into uniformly-sized 1/4" matchsticks.
Toss your French fries with the salt, pepper and about 1 tablespoon of olive oil in a large bowl.
Once your oil has reached 325ºF, drop the seasoned potato slices into the cast iron skillet, and cook them over a medium-high heat until crispy and tender, about 15-25 minutes. Keep them stirred with a wooden spoon, and adjust the heat as necessary to keep that temperature right around 325ºF.
While the French fries are cooking, heat the chili up in a microwave-safe bowl on high setting in the microwave for a few minutes, until hot and bubbly. Alternatively, you can also heat it in a medium saucepan over a medium heat on the stovetop.
Once your French fries are crisp and tender, remove the skillet from the heat and drain out as much oil as possible. I like to hold the French fries to the side of the skillet with a paper towel while tipping the pan over to the opposite side and letting the grease flow right on out.*
Finally, go ahead and pour the hot chili over the fries. Generously sprinkle the shredded cheese and green onions over top of chili, as well as any other toppings you may use.
Serve and enjoy with a big dollop of sour cream!