Tomato Tatin - Inspired Cuisine

Ingredients

• 1/2 cup honey
• 1/2 cup sherry or apple cider vinegar
• 4 medium ripe (red tomato)
• 1 large Spanish onion (sliced thinly)
• 1 tbsp oil or unsalted butter
• 1 tbsp sugar
• 1/2 tsp kosher salt (or to taste)
• 1/2 tsp freshly ground black pepper (or to taste)
• 1 package prepared pie crust
• 1 egg whisked to combine
• 1 tbsp water