Heat coconut oil in a large saucepan over medium heat until warm. Add in nutritional yeast, mustard, tomato paste, garlic, salt and turmeric and cook until mixed though, about 1 minute. 

Whisk in the almond milk, then bring to a simmer over medium heat. Add in the cauliflower florets and cashews and let simmer until cauliflower is very soft, about 20 minutes. 

Add the cauliflower-cashew mixture to a blender or food processor along with the vinegar and puree until very smooth, working in batches if needed. Depending on the power of your blender, this could take anywhere from 1-2 minutes. You don't want any grainy pieces of cauliflower or cashews, so make sure it's creamy and smooth before proceeding. 

Meanwhile, bring a large pot filled with salted water and able to be fitted with a steamer basket to a boil. Add the shells and cook, stirring often, until just tender, according to package time. Remove the shells with a slotted spoon (to keep the cooking water) along with 1/2 cup cooking water. Place the shells without the cooking water in a large bowl. 

Bring the water back to a boil and fit with a steamer basket. Add the broccoli and cover, cooking until bright green and not overly tender, about 3-4 minutes. 

Toss the hot macaroni with the cashew-cauliflower sauce until well coated. Season with salt and pepper, if needed/desired. Add in the broccoli and toss again, adding in any remaining cooking water to thin sauce, if needed. Serve hot.