Heat 1 tablespoon of the oil in a medium skillet over medium heat.
Add the salami and cook, stirring occasionally, until browned, 2 to 3 minutes. Transfer to a paper towel–lined plate.
Add the vinegar, mustard, honey, the remaining tablespoon of oil, and ¼ teaspoon each salt and pepper to the skillet. Whisk to combine.
Add the onion and cook, stirring occasionally, until it begins to soften, 3 to 4 minutes. Stir in the salami.
Divide the spinach among 4 individual plates and spoon the onion and salami over the top. Serve with the eggs, if desired.