Cut the bacon into 4 mm cubes. Cut the potatoes into 1 cm cubes. Cut the asparagus into 2.5 cm pieces. Finely chop the onion. Heat oil in a cast-iron skillet over medium heat. Fry the bacon, stirring often, until brown on all sides. It will take you about 10 minutes. Using a slotted spoon, place the bacon on paper towels and drain off the fat.
Add potatoes and cook for a couple of minutes. Season the potatoes with salt and pepper, then turn over to the other side and cook for a couple of minutes until the cubes are evenly browned. When the potatoes have been cooking for about 15 minutes, add the onions. Fry for another 5 minutes. Add the asparagus, cover the pot and cook for 5 to 8 minutes. It usually takes only 5 minutes to cook asparagus, but if it is thick, it will take longer.
Remove the lid, add the fried bacon to the skillet and cook for 1 more minute to reheat the bacon. Add seasoning to taste if needed. Serve immediately with scrambled eggs, goat cheese and green onions.