Cook frozen peas, asparagus, carrots and snow peas in large pot of boiling salted water until vegetables are crisp-tender, about 3 minutes. Drain. Transfer vegetables to bowl filled with ice water. Drain vegetables and set aside.
Heat 3 tablespoons oil in heavy large skillet over medium-high heat. Add shrimp and sauté until pink and cooked through, about 1 1/2 minutes. Transfer shrimp to medium bowl. (Vegetables and shrimp can be prepared up to 1 day ahead. Cover each separately with plastic wrap and then refrigerate.)
Heat remaining 3 tablespoons oil in heavy large pot over medium-high heat. Add onion and shallots and sauté until soft, about 5 minutes. Stir in couscous and tomatoes. Add wine and simmer until liquid is reduced by half, stirring often, about 10 minutes. Add vegetable stock and simmer until liquid is reduced by half and couscous is just tender, stirring often, about 8 minutes. Mix in reserved vegetables and whipping cream. Cook couscous over medium heat until mixture thickens and is creamy, about 3 minutes.
Stir Parmesan, butter and parsley into risotto. Add shrimp and mix until heated through and butter and cheese are melted and well blended, about 2 minutes. Season risotto to taste with salt and pepper. Divide risotto among 8 bowls and serve.