Preheat oven to 400°. Mist a large baking sheet (or 2 smaller sheets) with oil spray. Place the green beans and broccoli on top in a single layer, and liberally mist them with olive oil spray. Sprinkle on ½ teaspoon salt and 1 teaspoon ground cumin, trying your best to evenly distribute the seasonings. Roast in oven for about 20 minutes, or until veggies become nicely charred.

While veggies are roasting in the oven, prepare marinade for shrimp: In a large mixing bowl, combine olive oil, lime juice, remaining 1 teaspoon cumin, garlic powder, ½ teaspoon kosher salt, and ground black pepper (or crushed red pepper flakes for heat). Mix in the shrimp and let it sit for 15 to 20 minutes in the marinade.

When veggies reach 20-minute mark in oven, remove sheet pan(s) and nestle the shrimp among the vegetables. using a spatula, push the broccoli and green beans to the outer portion, creating an empty area in the middle for the shrimp. Place shrimp in center of pan and Return pan to oven to roast for another 5 minutes or until shrimp turn opaque, white/pink (small shrimp will take about 4 minutes, while larger prawns can take up to 12 minutes).

Squeeze some fresh lime juice over the top, and garnish with minced herbs and optional grated parmesan cheese.