CHEESE DIP: Combine cheese, evaporated milk, salsa, and jalapeños (if using) in a food processor and pulse until well blended. Transfer to a bowl, cover, and refrigerate for at least 2 hours and up to 3 days before serving.
TORTILLA CHIPS: Spread out tortillas in a single layer on 2 baking sheets. Set aside at room temperature overnight.
Fill a large skillet with ¼ inch of vegetable oil and warm over medium-high heat.
Quarter tortillas. Working in batches, fry in a single layer for 30 seconds, then flip tortillas. Fry until oil stops bubbling around tortillas and they look dry, about 1 minute.
Remove chips from oil and drain on paper towels. Once cool, sprinkle with lime juice (if using) and salt. Serve immediately, with chilled cheese dip.