Deconstructed Beef Wellies

Ingredients

• 1 pkg puff-pastry dough (397 g, thawed)
• 2-1/2 lb centre-cut beef tenderloin (cut into 1.5" thick medallions)
• 2 tbsp canola oil (divided)
• to taste salt
• to taste ground black pepper
• 2 tbsp butter (divided)
• 2 shallots (finely sliced)
• 1 green onions (finely sliced)
• 2 cups mushrooms (finely chopped)
• 2-1/2 oz chicken liver pate (thinly sliced)
• 1 egg
• 1 tbsp water (beaten with the egg to make a wash)
• 4 cups baby spinach