Over high heat, bring a large pot of salted water to a boil. Add the macaroni noodles and cook according to package instructions. Once the pasta is finished cooking, blanch the veggies in the pasta water for about 3 minutes or until bright green in colour.
Place the noodles and veggies in a medium casserole dish and set aside.
In a medium sauce pan, heat oil over medium heat. Whisk in the chickpea flour.
Add the almond milk, mustard, spice, and vinegar, whisking constantly to prevent clumps. Allow the mixture to come to a boil over medium low heat. Cook, whisking periodically, for about ten minutes or until thickened. Remove the sauce from the heat then whisk in the nutritional yeast, salt and pepper.
Pour the sauce over the noodles and veggies and give it a good stir so that the noodles are evenly covered in sauce.
In a small mixing bowl, combine all of the topping ingredients. Mix well, then sprinkle evenly over the macaroni.
Pop the macaroni into the oven and bake for 15-20 minutes. Broil for a further 2-3 minutes to brown up the top. Serve immediately or store in an air-tight container for up to three days.