Rinse the quinoa and cook it in 2 cups of water with a pinch of salt. Bring to a boil, then reduce heat and simmer for 15 minutes until the water is absorbed. Fluff with a fork and set aside.
While the quinoa cooks, combine the parsley, cilantro, garlic, 3 tablespoons olive oil, red wine vinegar, red pepper flakes, salt, and pepper in a bowl. Stir well to make the chimichurri sauce.
Toss the shrimp with 2 tablespoons of the chimichurri sauce and a pinch of salt and pepper. Brush the asparagus lightly with the remaining tablespoon of olive oil and season with salt and pepper.
Heat a grill or grill pan over medium-high heat. Grill the asparagus for 6 to 8 minutes, turning once, until tender with light char marks. Grill the shrimp for 2 to 3 minutes per side until pink and opaque.
Divide the quinoa among four plates. Top with grilled asparagus and shrimp. Spoon extra chimichurri over everything and serve with lemon wedges.