Preheat oven to 300 degrees F.
Toss together cherry tomatoes with olive oil, salt, pepper, garlic, and thyme. Spread on a baking sheet and bake for 40-45 minutes or until softened, stirring halfway through.
Meanwhile, cook pasta according to directions on the box. Drain pasta, rinse under cold water, and drain again. Toss with 1 teaspoon oil.
Prepare the leeks. Cut top green stalks off and discard. Slice white stems in half lengthwise and wash in between the layers. Thinly slice leeks into half-moon slices. Heat 1 tablespoon oil in a saute pan over medium heat. Add leeks and saute until browned and caramelized. If the pan becomes too dry, reduce heat and add 1-2 tablespoons of water. Remove from heat.
In the same pan, add halloumi and fry on both sides until golden brown. Remove from heat and cut into bite-size chunks.
Drain roasted tomatoes, reserving the oil. Whisk together oil with red wine vinegar, juice of ½ lemon, sugar, salt, and pepper. Toss together fusilli with caramelized leeks, halloumi, cherry tomato confit, oil dressing, fresh herbs, and pistachios. Adjust seasoning with salt and pepper. Serve warm, at room temperature, or cold.