The Spicy Lamb Grinder is a popular sandwich in Boise, Idaho and it's loaded with slices of juicy lamb, onion, and jalapenos covered with melted pepperjack cheese dipped in a savory au jus.
Heavily season steak with salt and pepper. Sit out and allow to come to room temp for 30 minutes.
Heat a cast iron skillet over medium high heat. Add oil. Once hot, place your steak in the skillet. Sear until golden brown, roughly 2 - 3 minutes. Then flip and sear the other side for a minute.
Lower the heat to medium. Add butter, garlic and fresh herbs. Occasionally spoon some of the butter over the steak. Flip and baste the other side.
Remove from the pan and set steak aside to rest. Keep herbs and garlic in the skillet and keep on medium.
After 15 minutes, thinly slice against the grain.
For the Au Jus
Add more butter if the pan is dry. Add minced onion and stir to combine. Season with salt and pepper. Cook until onion is translucent, about 2 - 3 minutes.
Add red wine and bring to a boil. Boil for a few minutes to reduce. Next, add the broth. Once boiling, reduce heat to medium low for a simmer. Simmer for 10 minutes. Taste and add more salt as necessary.
Place a small strainer over a bowl and dump the au jus into the bowl. Wipe out any excess moisture and return the skillet to a medium heat.
Everything Else
Butter both sides of your rolls and place in pan. Toast for a few minutes until golden brown. Remove from heat.
Add oil to the hot pan and add your bell pepper and onion. Sauté for a few minutes until soft and add salt and pepper.
Add in jalapenos, based upon desired heat level. Next, add in thinly sliced lamb, tossing evenly with the vegetables. Divide into three portions and top with two pieces of cheese each. Lower heat to medium low and cover with a lid or baking sheet for 2 minutes.
Remove the lid and carefully scoop your lamb and vegetable mixture to a toasted bun. Enjoy with the au jus for dipping.