You will need escalivada, a Spanish roasted vegetable dish which you can make ahead of time. Otherwise, you can roast the vegetables in the oven on another tray while the potatoes are roasting. Essentially, escalivada is roasted green and red pepper, onion and eggplant, then peeled, sliced thinly and tossed with salt and olive oil. This is part of the topping for the potatoes.
Preheat the oven to 375°F.
Slice potatoes evenly, about ¾" (2 cm) thick.
Drizzle approximately 1 tablespoonful of olive oil on the baking tray, then arrange potato slices to fill it (you can use a brush or your fingers to spread oil).
Brush another tablespoonful of olive oil on top of the potatoes, and place in the oven for approximately 30 to 40 minutes, or until potatoes are cooked.
While the potatoes are in the oven, deconstruct half of a chorizo sausage by peeling the casing off and mincing the sausage into tiny pieces.
Pour about a teaspoon of olive oil into a saute pan. Over medium heat, fry the chorizo sausage for about 2 or 3 minutes, just until browned.
Meanwhile, heat the cream in a small pot, then add the grated or sliced Manchego over medium-low heat, stirring constantly.
When the cheese has completely melted, remove from heat. (It should only take about 5 minutes). The potatoes should be ready by now!
It’s time to construct the tapas! You can leave the potatoes on the tray and assemble them there, however, I'm going to show you how I make them on a plate, though.
Spoon some of the cream and manchego mixture evenly on each potato slice. Next, add some of the escalivada. Finally, top with some chorizo. Serve immediately.