Preheat oven to 400 degrees and line a baking sheet with parchment paper. In a small mixing bowl, toss the cauliflower with olive oil, garlic powder, salt, and pepper and transfer to prepared baking sheet. Bake for 20 minutes, tossing halfway through.
Remove cauliflower from oven, drizzle half of the salad kit dressing over the cauliflower, and toss until the cauliflower is evenly coated. Let cool for 10 minutes.
On a large serving plate or bowl, toss together everything included in the salad kit (except dressing), cauliflower, and tomatoes. Drizzle remaining dressing over the salad and garnish with basil. Serve right away.