Preheat your outdoor grill or indoor cast-iron grill pan to medium-high heat. Lightly brush the grates with oil to prevent the sausages from sticking.

Prepare the fresh chimichurri sauce by combining the finely chopped parsley, minced garlic, chopped oregano, red wine vinegar, extra virgin olive oil, and red pepper flakes in a medium bowl. Season with the coarse salt and black pepper to taste, then stir well and set aside at room temperature so the flavors marry.

Place the chorizo sausages on the hot grill. Grill for 12 to 15 minutes, turning occasionally, until the casings are charred and crisp and the sausages are cooked through.

Carefully slice the grilled sausages in half lengthwise, without cutting all the way through, opening them up like a book. Place them back on the grill cut-side down for 1 to 2 minutes until nicely browned and slightly crispy.

During the last 2 minutes of grilling, place the split baguette portions cut-side down on the grill grates. Toast them until they are lightly golden brown and have visible grill marks.

Assemble the sandwiches by placing one grilled sausage inside each toasted roll. Generously spoon the fresh chimichurri sauce over the warm sausage, close the sandwich, and serve immediately while hot and juicy.