One day in advance prepare and apply a rub of cumin, salt, onion and garlic powder. Store the rubbed roast in zip lock plastic bag. One hour before cooking, add lemon juice to plastic bag, deflate as much as possible and set aside at room temperature

Drizzle bottom of roasting pan with olive oil and preheat oven to 450 degrees.

Cut the tops and bottoms off the peppers, cut in half vertically, seed and then use to cover roast. place roast in oven.

Reduce to 375 degrees after 10 minutes and baste every half hour. Check gauge after 40 minutes to gauge progress.

Roast should be taken out of oven once it reaches 125 degrees. Loosely cover while preparing sauce.

Deglaze pan with lemon juice and pour liquid and cooked peppers into a blender. Once blended add enough of the chicken stock to total enough liquid so that there is 3/4 cup for every tablespoon of butter. In a skillet heat butter , once butter has melted add anchovies and once dissolved gradually add flower, whisking continually. When flour is fully incorporated gradually add juice, whisking continually. if still too thick, add and incorporate more chicken stock .Once complete, taste for salt & pepper.