Preheat an oven to 220C and bring a medium pot of water to a boil.
Place the cauliflower into a large shallow bowl, drizzle over the olive oil, season with salt and pepper, mix well to combine then place onto a line baking tray and roast for 25 minutes, until golden.
Cook the macaroni in boiling water for 8 minutes then refresh under cold water and
drain.
Place a shallow frying pan over medium/high heat and add the butter. Once melted add
the onion and a good pinch of salt. Cook stirring often for 3 minutes then add the flour and cook that out, stirring, for 30 seconds before adding Califia’s Original Oat milk, a little at a time and stirring as you go to create a thick, smooth sauce.
Turn the heat down and allow the sauce to simmer, stirring often for 3 minutes then stir
through the nutritional yeast and adjust the seasoning with salt and pepper. Remove the
pan from the heat, grate half the cheese into the sauce and stir through to melt.
Add the pasta to the pan and stir through the sauce. Tip the macaroni and sauce into a baking dish and nestle in the cauliflower, spooning some sauce over them so it all fits nicely and the cauliflower is covered. Scatter the remaining cheese over the dish and return to the oven for 8 minutes, until bubbling and golden.
Serve scattered with parsley.