Peel potatoes and slice into 1/2" thick slices (or steak fries if you prefer). Toss in 2 Tbsp olive oil and bake at 375 degress for approx 30 - 40 minutes, until lightly browned and crisp on the outside, but soft on the inside. (I bake on a baking sheet.)
Meanwhile, brown ground turkey in non-stick pan sprayed with PAM, crumbling as it cooks. Stir in ketchup and mustard.
When potatoes are browned, transfer them to an 8x8" glass casserole. There will be more than one layer. Top with ground turkey mixture, then with cheese. Return to oven and bake approx 15 - 20 minutes, until cheese is melted.