Step 1

Prepare the choripán: Preheat a grill pan over medium-high heat or a grill to medium heat. Add the chorizo and let cook, turning occasionally with tongs as needed, until the sides are deeply seared and the center is fully cooked through, 30–35 minutes.

Step 2

Meanwhile, make the chimichurri: In a medium jar or bowl, add the parsley, onion, and garlic and stir briefly to combine. Add the olive oil, vinegar, salt, and pepper, and stir well. Let rest at least 15 minutes. (Chimichurri can be left out at room temperature for up to 12 hours before serving.)

Step 3

If desired, briefly warm the insides of the rolls over the grill as desired. You can also split the sausages lengthwise if desired.

Step 4

Place one cooked sausage into each roll. Slather one side of the roll and some of the sausage generously with chimichurri, and serve immediately.