Brennan's Eggs Hussarde

Ingredients

• 2 cups plus 3 tbsp. unsalted butter
• 1 clove garlic, finely chopped
• 1 scallion, finely chopped
• 1⁄4 yellow onion, finely chopped
• 1⁄4 cup finely chopped ham
• 1⁄4 cup minced mushrooms
• 1 tbsp. flour
• 3⁄4 cup beef stock
• 1⁄4 cup dry red wine
• 2 tsp. Worcestershire sauce
• 1⁄2 tsp. dried thyme
• 1 bay leaf
• 1⁄4 cup finely chopped parsley
• Kosher salt
• freshly ground black pepper
• 4 egg yolks, plus 8 poached eggs, for serving
• 1 1⁄2 tsp. red wine vinegar
• 1⁄4 tsp. cayenne pepper, plus more for serving
• 1 medium tomato, cut into 4 slices
• 1⁄3 cup grated Parmesan cheese
• 8 slices Canadian bacon
• 8 Holland rusks