Preheat oven to 350F. Grease or line 8 cups of a muffin pan.
With a spiralizer, spiralize 1 large sweet potato.
*NOTE: If not using a spiralizer, bake the sweet potato by wrapping in foil and baking in 350F oven for 1-1½ hr or until knife inserts easily. Remove from oven, cool, and mash).
Finely chop 1 small onion for ~2T and dice 3 mushrooms. Set aside together.
In a large skillet, brown 12oz ground breakfast sausage. Cool.
Place spiralized sweet potato, evenly, into muffin tins until they are about halfway full.
Crack 1 egg and place on top of spiralized sweet potato.
Top w/ ground sausage, 2T yellow onion & diced mushrooms. Sprinkle w/ S&P, cover w/ foil and bake for 15 mins.
Remove foil & cook for ~5 mins to crisp sweet potato if desired.