Lemony Salt and Black Pepper Cod on a Gratin Dauphinois Potatoes

Name: Lemony Salt and Black Pepper Cod on a Gratin Dauphinois Potatoes
Ingredients: 1 Cod Fillet; 20 g Cherry Tomato (halved); 2 Lemon (zest and Juice); Seasoning (Salt and Black Pepper); 2 Medium sized Plum Tomatoes (Finely Sliced); 2 Medium Sized Red Onion(Finely Sliced); 1 Lime (Juice only); 2 Garlic Cloves(minced); 1 Tsp Light Soy Sauce; 2 Tsp Demerara Sugar; 2 Large Baking Potatoes(finely sliced); 2 Tbsp Butter; Pinch Dried Thyme; Seasoning(salt and black pepper); 1 Cup Double Cream; 2 Cups Grated Cheddar Cheese; 1 Garlic Clove(minced)