Roughly chop garlic scapes. In food processor, pulse scapes until they're coarsely minced.
Add all remaining chimichurri ingredients to the food processor. Process the sauce for about 1 minute, scraping down sides in the middle if necessary. The should still look rustic and not completely pureed.
Allow to sit 15-30 minutes before serving. Garnish with finely sliced red chillies or a sprinkle of red chilli flakes if desired.
Turn barbecue to medium-high, around 400-450°F.
Chop vegetables into large pieces and place on a large platter. Small vegetables, like radish, can remain whole. Drizzle oil over top of vegetables and toss to coat. Sprinkle with a bit of salt.
Grill vegetables 4-5 minutes per side, flipping once nice char marks appear. Turn BBQ heat up or down as necessary.
Serve grilled vegetables on a large platter with a bit of chimichurri sauce drizzled over top, leaving the rest of the sauce on the side. Enjoy!