In an ovenproof skillet, heat 1 Tbsp of olive oil over medium heat. Add the onions with salt. Cook on low heat for 20 minutes, until caramelized. Remove from pan.
Add the bacon to the skillet until crisp. Remove from pan.
Over medium heat, add cubed sweet potatoes into the enough bacon fat and stir. Sprinkle with salt, pepper, rosemary and garlic allow to cook uncovered for about 2 mins.
Stir again, then cover the skillet and cook about 4 mins to soften, stirring once. Uncover and lower the heat to medium low to avoid excess browning if necessary. (If the potatoes are not softened on the inside, cover the skillet and cook for another 2 mins.)
Add in the caramelized onions and crisped bacon and make 4 indentations to crack in the eggs.
Place skillet in the preheated oven and bake until eggs are cooked to desired doneness.
Once done, garnish with spring onions. Serve immediately.