Pastrami Pastry Puffs - Side Dish - Kosher Recipe

Ingredients

• 1 onion, diced
• 2 tbsp. oil
• 2 portabella mushrooms, sliced
• ½ red pepper, finely sliced
• 4 pieces non-dairy puff pastry (5 x 5 in. each)
• 2 tbsp. mustard
• ½ lb. pastrami, cut into strips
• 2 eggs
• Sesame seeds