Melt butter in a medium saucepan over medium-high heat. Add the onion and cook for 4-6 minutes, until translucent.
2. Step
Add the jalapeño and stir for 4 minutes, until soft. Add the garlic and cook for about 1 minute.
3. Step
Sprinkle in the cornstarch and stir for two minutes. Add the evaporated milk and stir for 3 minutes, or until the mixture thickens.
4. Step
Slowly add the cheese ½ cup (50 g) at a time. Stir constantly until the cheese is completely melted.
5. Step
Remove the queso from the heat. Line a baking sheet with parchment paper, then pour the queso over it. Use a spatula to spread the queso in an even layer about an ⅛ inch (3 mm) thick.
6. Step
Freeze for three hours.
7. Step
Remove the queso from the freezer and transfer to a cutting board. Carefully cut the queso horizontally into 7 rows, about 2½-inches (6-cm) apart.
8. Step
At the end of the bottom row, cut a triangle. Continue cutting triangles down the length of the row. Repeat with the remaining rows.
9. Step
Place the flour, eggs, and tortilla chip crumbs in 3 separate medium bowls.
10. Step
Heat the oil in a large pot until it reaches 350°F (180°C).
11. Step
Toss a triangle of queso in the flour. Tap off any excess flour, then dip the piece in the egg, then toss it in the tortilla chip crumbs. Repeat with the remaining queso chips.
12. Step
Fry the breaded queso chips 3-4 at a time, until golden brown, 15–30 seconds.
13. Step
Drain the chips on a wire rack or paper towels.
14. Step
Garnish with cilantro. Serve with guacamole, pico de gallo, and sour cream.
