Adam Liaw's American spinach salad

Ingredients

• 3 eggs 
• 2 tbsp olive oil
• 80g speck or thick-cut bacon, cut into lardons
• 2 tbsp apple cider vinegar
• 1 tsp Dijon mustard
• ½ tsp sugar
• salt and black pepper, to season
• 4 button mushrooms, very finely sliced
• ½ red onion, very finely sliced
• 120g baby spinach leaves, washed and picked