Preheat the oven to 425 degrees. Wash the potatoes well and peel if desired (I like to leave the peel on for extra texture and flavor). Cut the potatoes into strips or “fries”, approximate 1/2 inch thick.
Place the fries in a bowl and add the olive oil and worcestershire sauce. Toss to coat. In a small bowl combine the chili powder, smoked paprika, garlic powder, salt, pepper, and cornstarch. Stir to combine the spices, then add to the bowl with the fries. Toss to coat once more.
Line a baking sheet (or two) with foil and spray lightly with non-stick spray. Spread the fries out on the baking sheet so that they are in a single layer and not piling up on each other. Use two baking sheets if needed. Bake for 40 minutes, stirring once halfway through.
After 40 minutes, they should be slightly brown and crispy on the edges. If you cut your fries thicker, they may need more time in the oven. Transfer the fries to an oven safe casserole dish. Top with the shredded cheese and return to the oven for about 5 minutes more or until the cheese is fully melted. Chop the onions while the cheese is melting. Top the fries with the green onions and dollops of sour cream. Serve immediately!