1. In a bowl, add the shallot, red wine vinegar and sugar. Stir to combine and allow to pickle for 15 minutes. Arrange the little gem and rocket onto a serving plate. Add the shallows and drizzle with olive oil. Grate over the Castello® Tickler Extra Mature Cheddar, and sprinkle with chives. Season with black pepper, set aside whilst you make the toastie.
2. In a large frying pan over a medium heat, add 1 tbsp of olive oil. Once hot, add the chopped mushrooms, and sauté for 10 minutes until they have reduced in size, released their juices, and started to brown in colour.
3. Next, add the butter and minced garlic, and cook until the butter starts to brown, and the mushrooms are soft and full of flavour. Remove from the heat and add the chopped parsley and season to taste.
4. In a small bowl, mix the softened butter and grated Tickler Extra Mature.
5. Take the pieces of sourdough and spread the bread with the cheesy butter on one side. Next, turn them over and spread with the Dijon mustard. Top one piece of bread with half the crumbled Castello® Tickler Extra Mature Cheddar, mushrooms, a sprinkling of chives, the remaining Extra Mature, and finally the other slice of bread.
6. In the same frying pan that the mushrooms were cooked in, fry the bread over a low to medium heat for 5 minutes on each side, until golden and toasted and the cheese has melted. You can use a sandwich press here if you have one!
7. Slice in half and serve with your salad and a sprinkle of chives. Dip your toastie into more Dijon mustard if you fancy!