"I had a little bit of mashed potato, half a roasted red pepper, and a pound of scallops left over from a ceviche recipe. This was fast and fun: no recipes, no measuring, just intuitive cooking. Which is what made it so good."
Set oven rack about 6 inches from the heat source and preheat the oven's broiler. Line a baking sheet with aluminum foil. Place the pepper, cut-side down, on the prepared baking sheet.
Cook pepper under the preheated broiler until pepper skin blackens and blisters, 5 to 8 minutes. Place blackened pepper into a bowl and tightly seal with plastic wrap. Allow the pepper to steam as it cools, about 20 minutes. Remove and discard skin; thinly slice pepper.
Stir mashed potatoes, egg, bread crumbs, salt, and black pepper together in a bowl until smooth.
Heat olive oil in a large nonstick skillet over medium heat. Working in batches, drop batter by spoonfuls into hot oil and flatten out to form a small pancake. Cook until golden and crispy on one side, about 7 minutes. Flip and cook until golden and crispy on the other side, 5 to 7 minutes more. Wipe skillet clean with a paper towel.
Place scallops in a bowl and season olive oil, cayenne pepper, and salt.
Heat the same nonstick skillet over high heat. Place scallops in the center of the skillet; place red peppers in a pile in the side of the skillet. Cook scallops until a golden crust develops, 3 to 4 minutes. Transfer scallops to a plate, leaving peppers in the skillet.
Cook and stir peppers, basil, butter, and capers together in the hot skillet; pour water into skillet, stir sauce, and remove from heat.
Arrange pancakes in a single layer on plates or a platter; place 2 to 3 scallops on each pancake. Top with pepper sauce.