1. Heat a gas or charcoal grill to high and grill the whole peppers, turning occasionally, until their skin blackens, about 10 min. Place in a paper bag, close securely and set aside to cool.
2. Season the steak on all sides with salt (in moderation) and pepper. Place on one side of the grill and cook with the lid down for 10 min. Open grill and turn off heat under the meat (the other elements will not be turned off). If using a charcoal grill, move the coals to the other side of the grill so they are not directly under the meat. Lower cover and continue cooking about 25 min., or until an instant read thermometer reaches 135°F.
3. While the meat is grilling, remove the cooled peppers from the bag and peel off the blackened skin. Seed and roughly chop the flesh. Using an immersion blender or food processor, blend the peppers with the almond butter, cumin, vinegar, oil, garlic and hot sauce. Season with salt (in moderation).
4. Transfer the steak to a serving platter and cover loosely with foil. Allow to rest about 10 min.
Serve with the romesco sauce.
Per serving: 249 calories, 17g fat, 5g saturated fat, 72mg cholesterol, 103mg sodium, 3g carbohydrate, 1g fiber, 2g sugar, 23g protein