Preheat oven to 450 degrees.
In a large bowl, combine onion, bell pepper, asparagus, garlic, shrimp, oil, salt and pepper and spices.
Toss to combine well.
Spray baking sheet with non-stick cooking spray (if needed).
Spread shrimp, bell peppers and onions on baking sheet. Do not overcrowd it in the tray, either use 2 trays or cook it in 2 batches
Cook at 450 degrees for about 10-12 minutes until shrimp is cooked through. Squeeze juice from fresh lime over shrimp mixture and top with fresh cilantro.
Divide the brown rice/quinoa evrnly between 4 bowls, and add the shrimp and veggies fajitas on top.
You may serve it right away or keep it in the fridge in air-tight containers for up to 4 days and reheated before serving.