Pre-heat oven to 375°F.
Bring shallots, cream, salt, pepper, thyme, and garlic cloves to a simmer in a small saucepan over low heat; cook until shallots and garlic are very soft, 15–20 minutes. Let cool slightly. Transfer to a blender; blend until smooth.
Arrange potato slices in prepared dish, fanning out a handful at a time and placing in dish at an angle. Shingle as you work until bottom of dish is covered. Tuck smaller slices into any gaps to fill. Pour cream mixture over potatoes and cover dish tightly with foil. Bake potatoes until tender and creamy, 60 minutes. Let cool.
Place rack in highest position; heat broiler. Remove foil and top potatoes with gruyere. Broil until cheese is bubbling and top of gratin is golden brown, 5–10 minutes.
In a medium bowl, combine the butter and all the spices until well mixed. Place the mixture onto a large piece of plastic wrap, and shape into a log. Roll the plastic wrap shut, and twist the ends tight. Transfer the butter to the refrigerator to firm. Can be stored in freezer for a month.
Mix blue cheese, mayonnaise, sour cream, buttermilk, lemon juice, garlic powder, hot sauce, pepper, in a medium bowl. Season with salt and more lemon juice if needed.
Cook bacon in skillet over medium-high heat, turning occasionally, until brown and crisp, 6–8 minutes. Transfer to paper towels to drain.
Cut tomatoes in half and season with olive oil salt and pepper. Cut lettuce into quarters. Ladle dressing all over lettuce, spoon over cherry tomatoes, crumble bacon over top and garnish with dill.
Once you have all your sides prepared cook steak according to directions on package.
Slice a piece of Cajun butter and serve over top of steak and accompanying sides.