Dry carrots with paper towels or a kitchen towel. Rub carrots with oil and sprinkle with salt and pepper.
Lay flat on a baking sheet and place in pre-heated oven. Bake carrots for 20 minutes, then flip and bake another 10 minutes. This is for average sized carrots and cooking time will vary depending on the size of the carrots so adjust if needed.
During the last 15 minutes of cooking time, start making sauce by heating oil in a small sauce pan over medium heat. Sauté onion in oil for about 5 minutes until it starts to brown. Add garlic and cook 1-2 minutes longer. Pour in broth and bring to a boil.
Remove broth from heat and pour into a blender or food processor. Drain cashews and add to blender along with nutritional yeast. Blend until smooth and creamy. Add water if needed, just enough to make it pourable but still thick and sauce like. Season to taste with salt and pepper.
Remove carrots from oven and place on serving plate. Pour sauce over carrots and sprinkle with parsley. Serves 2 as a side or one as a main dish.