Finely mince the parsley. Whisk the parsley, garlic, red wine vinegar, olive oil, dried oregano, red pepper flakes, and salt and pepper until the olive oil and red wine vinegar are emulsified. You can also use an immersion blender.
If needed, prepare the quinoa according to package directions. Quinoa is cooked at a 1 part quinoa to 2 parts water ratio. Pat the shrimp dry with paper towels and season with salt and pepper.
Meanwhile, place a pan over medium heat. Once hot, add 1 tablespoon of olive oil. Add the zucchini and summer squash. Season with salt and pepper. Sauté for about 10 minutes, or until tender and lightly browned. Remove the vegetables from the pan and set aside.
Add the remaining avocado oil to the pan. Once shimmering, add the shrimp and cook for 3-4 minutes per side, or until the shrimp is opaque and cooked through.
Serve quinoa, shrimp, zucchini and squash, and black beans drizzled with chimichurri.