Step 1

Arrange 2 racks to divide the oven into thirds and heat the oven to 425ºF (or the temperature on the package directions for the fries).

Step 2

Divide 1 (28- to 32-ounce) bag frozen seasoned french fries between 2 rimmed baking sheets and arrange into a single layer. Bake until the fries are light golden-brown and crisp, stirring the fries halfway through and switching the baking sheets between racks, 25 to 35 minutes total or according to package directions. Meanwhile, prepare the toppings and cheesy beef.

Step 3

Cut 1 medium Roma tomato into small dice (about 1/2 cup). Thinly slice 2 medium scallions (about 1/4 cup). Grate 4 ounces sharp cheddar cheese on the large holes of a box grater (about 1 cup). Cut 4 ounces Velveeta processed cheese into 8 pieces.

Step 4

Heat a medium frying pan over medium-high heat until hot. Add 8 ounces ground beef and season with 1/2 teaspoon kosher salt. Cook, stirring occasionally and breaking the meat up into bite-sized pieces with a wooden spoon, until cooked through and starting to brown, about 3 minutes.

Step 5

Sprinkle with 1 tablespoon taco seasoning and stir to combine. Stir in 1/4 cup water and simmer until mostly evaporated, 1 to 2 minutes. Taste and season with more kosher salt as needed. Add 1 cup whole or 2% milk and bring to a full simmer. Add the cheddar and Velveeta, and stir until the cheeses are completely melted. Remove the pan from the heat and cover to keep warm.

Step 6

When the french fries are ready, transfer all the fries onto one baking sheet (or large serving platter) and arrange into an even layer. Spoon the cheesy beef (if it’s cooled off, rewarm over low heat first) evenly over the fries. Dollop 1/3 cup sour cream in small spoonfuls over the fries. Sprinkle with the tomatoes and scallions. Serve with hot sauce if desired.