Heat olive oil in a skillet over low heat. Add onions and let caramelize, stirring occasionally. About 10-12 minutes. Remove onions from skillet and set aside. Increase heat to medium.
Cut sausage links into bite size pieces. Add sausage pieces to skillet and cook through. Remove from skillet and set aside.
Add diced sweet potatoes to skilled. Add 2 tbsp of water and immediately cover to steam potatoes. After 3 minutes, remove lid and stir sweet potatoes. Continue cooking until sweet potatoes are cooked and have a light brown crust. Stir in garlic, red pepper flakes, and seasonings to sweet potatoes. Cook another minute. Stir in caramelized onions and sausage. Remove from heat.
While potatoes are cooking, bring a medium size pot of water to a boil. Once boiling, reduce heat to a simmer. Crack one egg into a small bowl. Carefully drop the egg into the simmering water. Let cook for 3 minutes. Remove poached egg from water with a slotted spoon. Place egg on a paper towel lined plate to soak up excess water. Repeat with remaining eggs.
Sprinkle parsley and crumbled feta over sweet potatoes. Top with poached eggs.