1. preheat the oven to 350 degrees f. line a baking dish with parchment paper. 2. peel and thinly slice the potatoes using a mandoline or a sharp knife. 3. in a large mixing bowl, combine the sliced potatoes, salt, parsley, paprika, butter, and cornstarch. toss to coat the potatoes evenly. 4. layer the coated potato slices in the prepared baking dish. 5. cover the dish with parchment paper and bake for 1-1.30 hr. 6. remove from the oven and let cool. 7. place a weight on top of the baking dish and press down to eliminate any gaps or air pockets. refrigerate for at least 6 hrs or overnight. 8. remove the potato block from the baking dish, trim all four sides and cut it into smaller rectangular pieces. 9. heat a pan on medium-high heat with olive oil. place the potato cubes onto the pan and cook until tender and golden brown. 10. serve the potato pavé with a small piece of unsalted echire butter and a dollop of caviar on top.