Pre-heat oven to 400 degrees. Line a baking sheet with aluminum foil. Toss tomatoes with 1 tsp olive oil and minced garlic. Season with salt and pepper. Roast for 20 minutes, then set aside to cool.
Whisk dressing ingredients in a small bowl.
Cook couscous according to package directions, then rinse with cold water and toss with dressing in a large bowl.
Place trimmed asparagus in a microwave safe dish and cover with a very damp paper towel. Microwave for 2 1/2 minutes until asparagus is bright green. Add asparagus to an ice bath to stop the cooking. Drain and pat dry, then chop into 1-2" chunks.
Add all remaining ingredients to the couscous and toss until evenly coated with dressing.