Preheat the oven to a 180C fan.
Toss the veggies in a baking dish with the Cajun spices and olive oil and place in the oven for 1 to 1,15 hours, until cooked through and well caramelized, stirring a bit at midtime to ensure homogeneous cooking and coloring.
In the meantime, cook the pasta as per pack instructions (usually, 10 minutes in boiling water), drain them well and add in the veggies once these are cooked.
Drizzle the lemon juice, stir and serve warm.