Ploughman's pie recipe

Ingredients

• 2 tbsp oil (e.g. rapeseed)
• 1 tbsp cider vinegar
• 1 tsp sugar (any kind)
• 4 medium red onions, each cut into 6 wedges
• 3 ripe medium tomatoes, cut into quarters
• 150g mature cheddar
• 120g thick cut ham (shredded ham hock also works well)
• 12-16 silverskin pickled onions, drained
• 1 tbsp thyme leaves, plus extra to serve
• 1 x 500g block shortcrust pastry
• plain flour to dust
• 175g sweet pickle or chutney of your choice
• beaten egg to glaze
• 10g finely grated Parmesan (or extra cheddar)
• flaky sea salt