COOK IT.
Whisk together ingredients for the honey mustard dressing and set aside.
Bring a large pot of salted water to a boil and cook pasta according to package instructions until al dente. Drain, drizzle with olive oil, and let cool at room temperature.
Meanwhile, preheat the grill to medium-high heat.
In a large mixing bowl, toss together zucchini and bell pepper with paprika, garlic powder, a drizzle of oil, salt & pepper.
Drizzle oil separately onto red onion and halloumi slices, and season with salt & pepper.
Grill vegetables until lightly charred but still crisp, 3-4 minutes per side. Wrap cooked red onions with aluminum foil until ready to serve. Grill halloumi for 3-4 minutes per side.
Cool vegetables and halloumi slightly and cut into bite-sized pieces.
In a large serving bowl, toss together pasta, vegetables, halloumi, and sun-dried tomatoes with the honey mustard dressing. Toss in tuna if using. Finish with basil and more salt & pepper.