Gochugaru has a pretty clean fruity taste, so it is hard to identify a suitable substitute. The are not as earthy as a lot of Mexican or New Mexican chilies, the closest may be Ancho or California dried chilies that you grind your self in a blender; another option could be Aleppo pepper. These ribs should not be confused with Korean barbecue galbi or bulgogi.
Gochugaru Spare Ribs:
East Meets West Barbecue Sauce:
Method: Indirect heat
Remove membrane from the backside of the ribs by taking a sharp knife to lift the corner and then pull down and off using a paper towel for better grip. Rub each rack with 1 teaspoon of toasted sesame oil. Place on a sheet pan; cut the racks in half for easier handling, if desired. Combine the rub ingredients and sprinkle over fronts and backs of ribs make sure everything get coated and all of the rub is on the ribs (not on the pan); use all of the rub. Let cure at room temperature for one hour or cover and place in refrigerator for up to three days. Make the East Meets West Barbecue Sauce.
Set up grill for indirect cooking with medium-low heat (temperature around 300°F). Place drip pan under the grates where the ribs will sit and place grates back on the grill. For gas: make sure you have enough gas. For charcoal: bank the coals to one side; every hour, check on the temperature and add 10 unlit briquettes or similar amount of charcoal.
Place the ribs bone-side down over drip pan; if short on space, shingle the ribs on top of each other. Close grill and cook 3 1/2 to 4 hours for spare ribs (2 ½ to 31/2 hours for baby back ribs); or until the meat has shrunk back from the bones and the ribs are fall apart tender. Every 30 minutes or so, rotate ribs around the grill to ensure even cooking.
About 15 minutes before ribs are done, turn the heat up to medium. Place the ribs meat-side down over the fire and cook for a couple minutes to crisp them up and render any remaining fat. Generously brush with sauce. Return the ribs meat-side up to the indirect side of the grill and brush on more sauce. Cover grill and cook an additional 10 minutes. Transfer the ribs to a cutting board and tent with foil. Let rest 10 to 15 minutes. Brush with more and cut into individual bones for serving. Serve hot or at room temperature with extra sauce on the side.
East Meets West Barbecue Sauce (makes 3 cups)
Combine all ingredients in a blender and puree until smooth. Transfer to a medium saucepan and bring to a simmer for 10 minutes, stirring occasionally. Remove from heat and cool to room temperature before storing in the refrigerator in an air-tight container. The sauce will keep in the refrigerator for up to a couple weeks.