How to Make It
Preheat broiler with oven rack 6 inches from heat.
Stir together olive oil, garlic, crushed red pepper, and 3/4 teaspoon of the thyme in a small bowl. Place shrimp and tomatoes in 2 separate bowls. Combine zucchini and yellow squash in a third bowl. Toss each with one-third of oil mixture.
Heat a rimmed baking sheet in the oven, 2 minutes. Add zucchini, squash, and lemon (flesh side up) to hot baking sheet, and bake until squash begins to soften, about 5 minutes. Add tomatoes, and bake until tomatoes begin to burst, about 5 minutes. Stir in shrimp; bake until shrimp are cooked through and zucchini is tender and lightly browned, about 5 minutes. Remove from oven, and sprinkle with salt and pepper. Squeeze juice from roasted lemon over vegetables; stir to combine.
Cook rice according to package directions. Divide rice, shrimp, and vegetables among 4 plates. Top evenly with remaining 3/4 teaspoon thyme.