In a mixing bowl, combine the flour and salt.
Add the butter, using a pastry blender or two forks to incorporate it into the flour until crumbly.
Stir in the egg until combined.
Fold in the cheese and jalapeños until the mixture forms a dough.
Shape into a ball, wrap in plastic, and refrigerate for 1 hour.
Preheat the oven to 400°F (200°C).
Form the dough into 1-inch balls on a parchment-lined baking sheet, spaced 2 inches apart. Flatten slightly.
Bake for 14-18 minutes or until the edges brown.
Cool on the sheet for 5 minutes, then transfer to a wire rack.