Preheat the grill to 400℉.
Bring a large pot of water to boil and boil potatoes until just fork tender. Drain and set aside.
Chop the zucchini, yellow squash, red bell pepper, and yellow onion into large pieces.
Gently toss all of the vegetables in the olive oil and creole seasoning. Place all of the vegetables on skewers.
Grill at 400℉ for 10-15 minutes, turning every 3-4 minutes until the vegetables are tender and starting to become crisp on the edges.
Remove from heat and drizzle with chimichurri sauce.