For the romesco sauce: Preheat the oven to 450 degrees F.
Cut off the top of the garlic just to expose the tips of the cloves. Sprinkle with salt and pepper and drizzle with olive oil. Wrap tightly in foil and roast until the cloves are golden brown and tender, about 45 minutes. Open the foil and allow the garlic to cool until cool enough to handle, then scoop the cloves out using a fork or knife or squeeze the whole head with your hand, turning it upside down to release the cloves into a small bowl.
Puree the bread, roasted peppers, almonds, vinegar, dill, parsley, basil, anchovies, tomato and roasted garlic pulp in a blender on high speed, just blending enough so that there is still some texture to the sauce. Set aside until ready to use.
For the hanger steaks: Preheat a grill on high heat.
Combine the chile powder, garlic powder, pepper and seafood seasoning in a small bowl. Sprinkle the steaks on all sides with salt, then rub with the spice mixture. Grill the hanger steak on all sides, rotating so the char is even, about 10 minutes for an internal temperature of 125 degrees F or medium-rare. Allow the steaks to rest for 10 minutes.
Carve the steaks by cutting large pieces against the grain. Serve with a squeeze of lime and the romesco sauce.