Preheat your oven to 425℉/218℃ convection roast and line a large baking sheet with parchment paper.
Arrange the chopped vegetables on your tray and roast them for 15 minutes, or until the edges are golden brown.
Meanwhile, bring a large pot of generously salted water to a boil, and cook your pasta according to package directions for 'al dente' pasta. Drain it, (BUT RESERVE ¼-1/2 cup of the water) return it to the pot, and set it aside.
Meanwhile, make the pesto. Add the basil, garlic, and lemon juice to your food processor and process until finely chopped. Then with the processor running, slowly add ¼ cup (or more if needed) of the reserved starchy water to reach your desired consistency. Taste for salt and pepper and adjust as needed.
Add the pesto and the roasted veggies to the pot of drained pasta, mix well, and serve.
Notes
Salt your cooking water. Make sure to add enough salt to your pot of water for the best texture and flavour. Here’s a handy guide to help you salt your water perfectly each time.
Cook to 'al dente' texture. Do not overcook! Al dente means that the pasta is still firm once cooked, giving optimal texture in every bite. To ensure it does not overcook, start taste testing a few minutes before the package says it will be ready. It should be tender, but still firm.