Heat a smoker to run at 250 degrees F.
Trim the steak of any silverskin/membrane on the surface using a filet knife. This step isn't essential, but here's why you want to do it: unlike fat, which renders during cooking, silverskin doesn't break down and can result in a chewier bite.
Season well with salt and pepper, then place into the smoker. If you have one, insert a probe to monitor temperature. If you don't have a probe device, use a meat thermometer to start checking the internal temperature at about 1.5 hours in.
Once the internal temp at the thickest part reaches 130-135 degrees, remove the meat from the smoker and wrap tightly in foil or butchers paper. Allow to rest 20 minutes.
After resting, slice against the grain into 1/4" strips and serve immediately with the Green Romesco.
Green Pipian Romesco Sauce
In a dry skillet, toast the pumpkin seeds until they just start to turn golden brown and pop. Do not let them cook beyond this stage or they will be bitter. Remove from pan and set aside.
Toast the sesame seeds until golden, then remove and pour into bowl with pumpkin seeds.
Add 1 tbsp oil to the pan, then brown the onion, garlic cloves and poblano strips until they soften and a little color has developed.
Place the pumpkin and sesame seeds in a blender or food processor. Add a little of the chicken stock. Blend until combined.
Add the peppers, onions, garlic and tomatillos, along with the rest of the chicken stock. Blend until well combined, about 3-5 minutes. If the mixture is sticking to the sides and too dry, add the oil and a little extra chicken stock.
Finally, add the cilantro bunch and the lime juice, as well as 1 tsp salt. Blend, then add more salt to taste. Will store in an airtight container in the fridge for up to a week.