Cookwith - Unhinged Keto Steak & Egg McMuffin-Inspired Breakfast Tower

Ingredients

• 4 large eggs
• 1 lb filet mignon or tenderloin steak (cut into 4 thick medallions)
• 1/4 cup mayonnaise
• 1 tbsp Dijon mustard
• 1 tsp lemon juice
• 4 slices sharp cheddar cheese
• 4 large portobello mushroom caps, stems removed
• 2 tbsp avocado oil
• 1/2 small red onion, thinly sliced
• 1 cup baby arugula
• Kosher salt, to taste
• Freshly ground black pepper, to taste