Turn broiler on high. Place peppers, cut side down on a baking sheet and drizzle with olive oil. Rub olive oil into skin and place under broiler for 8-10 minutes, until skin is nicely charred. Remove from oven and let cool slightly. Preheat oven to 425.
In a food processor, pulse together garlic, almonds, tomato paste, apple cider vinegar, and paprika. Add in charred red pepper and pulse. Slowly add in olive oil and pulse until sauce is thick but without any clumps. Set aside.
For the remainder:
Heat 1-2 tablespoons of olive oil in a heavy bottomed skillet over medium-high heat. Add potatoes and a couple pinches of salt and cook, stirring occasionally, for about 25 minutes.
Place cod on baking dish and drizzle with remaining 1 tablespoon olive oil and some Kosher salt. When potatoes have about 15 minutes left, place fish in oven for 12 minutes.
Spoon ¾ of romesco sauce onto potatoes and stir to coat. Season with salt and pepper to taste.
To plate, place fish on top of potatoes and spoon remaining romesco sauce on fish.