If using fresh corn on the cob, heat a grill pan (or BBQ) over medium heat. Brush corn with a light layer of olive oil (or canola oil) and grill on all sides until charred and tender (about 10-12 min.) . If using cooked/thawed corn proceed to the next step.
Combine corn, shrimp, onions, Sriracha, garlic, salt, chorizo in a large bowl. Add half each of basil and tomatoes and toss to combine.
Heat olive oil in a large skillet over high heat. Add shrimp mixture and cook until shrimp turn pink (about 4-5 min.).
Divide shrimp mixture between two plates or shallow bowls. Top with grated lemon and drizzle with lemon juice. Add remaining tomatoes and basil.