Heat 1 tablespoon of the oil in a medium skillet over medium heat. Add the salami and cook until sizzling and browned, 2 to 3 minutes. Remove from heat. Using a slotted spoon, remove and set aside the salami, leaving the rendered fat. Add the mustard, honey, vinegar, salt, pepper, and the remaining 1 tablespoon of oil and whisk together to form a thin emulsion. Add the onion and salami and return to medium heat. Cook just until the onion wilts, about 1 minute. Divide the spinach among serving plates. Pour the hot salami dressing over the greens. Serve with the eggs, chopped, if desired.
Tip: With its casing uncut, a whole salami can last for months if stored at a cool room temperature. Once cut, it can be refrigerated for up to 2 weeks if tightly wrapped.