Wash and scrub the potatoes. Cut each potato into 1/4-inch to 3/8-inch thick fries (matchstick style or slightly thicker). Rinse cut fries under cold water until water runs clear to remove excess starch, then dry thoroughly with clean kitchen towels or paper towels.

Par-cook (optional for crispier fries)

Place fries in a large pot of cold water, bring to a simmer and simmer 3 minutes. Drain and spread on a tray to dry completely. Alternatively, blanch in oil at 325°F (160°C) for 3 minutes and drain.

Fry

Heat 1 cup vegetable oil in a heavy skillet or deep fryer to 350–375°F (175–190°C). If using oven, preheat to 425°F (220°C) and toss fries with 1–2 tbs oil. Fry fries in batches without crowding until golden and crisp, about 3–5 minutes per batch. If using oven, bake 20–30 minutes turning halfway until golden and crisp. Drain on paper towels and immediately season with 1 tsp salt and 1 tsp black pepper.

Chili

Cook aromatics and beef

Heat 1 teaspoon vegetable oil in a large skillet or medium saucepan over medium-high heat. Add the diced onion and cook until softened and translucent, about 4–5 minutes. Add minced garlic and cook 30 seconds until fragrant. Add the ground beef and break it up with a spatula; cook until browned and no longer pink, about 6–8 minutes. Drain excess fat if necessary.

Simmer chili

Stir in tomato paste and cook 1 minute. Add tomato sauce, beef broth, Worcestershire sauce, chili powder, cumin, paprika, brown sugar, 1 tsp salt and 1/2 tsp black pepper. Bring to a gentle simmer, then reduce heat to low and simmer uncovered 12–15 minutes to thicken, stirring occasionally. Taste and adjust seasoning. The chili should be thick enough to spoon over fries (add up to 1/4 cup more broth if too thick). Keep warm.

Assemble & Serve

Preheat oven broiler to high (if you want melted cheese that is bubbly and slightly browned). Place the cooked fries on an oven-safe platter or baking sheet in a single layer or slightly piled.

Spoon warm chili evenly over the fries, spreading to cover most of the surface.

Scatter the shredded cheddar cheese evenly over the chili-covered fries.

Broil 2–4 minutes until cheese is melted and bubbly (watch closely to avoid burning). Alternatively, return to a 375°F (190°C) oven for 5–8 minutes to melt the cheese.

Remove from oven. Top with sliced jalapeño (if using), sliced green onions, and dollops of sour cream if desired. Serve immediately and enjoy.