Barbecued Celeriac Burger Recipe

Ingredients

• 1 large celeriac
• 1 tbsp of olive oil
• 1 tbsp of wholegrain mustard
• 100g of ketchup
• 15g of dark brown sugar
• 15ml of cider vinegar
• 1/2 tsp Marmite
• 1/4 tsp garlic granules
• 1 pinch of smoked paprika
• 1 dash of Tabasco
• lemon juice, to taste
• 1 pinch of cracked black pepper
• 1 pinch of celery salt
• 4 bread buns
• 1 tomato, sliced
• gem lettuce, leaves washed
• 1 red onion, sliced
• gherkins
• ketchup, vegan mayonnaise, mustard or any other burger condiments you like