Place the eggplant, red pepper, and grape tomatoes on a large roasting pan. Drizzle with enough olive oil to coat all the veggies. Season generously with salt and pepper. Toss to combine. Roast for 40-45 minutes until all vegetables are tender and tomatoes and blistered open.
Remove from oven and allow to cool briefly. Place vegetables in a food processor and process until mostly smooth but slightly chunky. Pour into a pan large enough to hold the vegetables and the pasta and keep warm over a very low heat.
While preparing the vegetables, cook the pasta in plenty of salted boiling water according to package directions (for al dente). Drain but save 1-2 cups of the cooking water.
Add the pasta to the vegetables, mix to combine, and add enough of the cooking water to get a creamy consistancy. Season with salt and pepper, if necessary. Pour into a serving dish and keep warm.
In a small dry pan over medium heat, toast the pine nuts until golden brown (be careful not to burn). Sprinkle the pine nuts over the pasta and serve immediately.