Serves 4 to 6
2 tbsp minced garlic
2 tbsp pure chile powder
1 tbsp dried oregano
1 1/2 tsp ground cumin
Kosher salt and freshly ground black pepper
1/2 cup grapefruit juice, preferably fresh
2 small pork tenderloins (1 to 1 1/4lb. each), trimmed
1 small jicama
2 ripe avocados
1/2 small red onion
2 tbsp fresh lime juice
Position a rack in the center of the oven and heat the oven to 450ºF. In a small bowl, combine the garlic, chile powder, oregano, cumin, 1 tsp. each kosher salt and black pepper, and enough of the grapefruit juice (about 1/4 cup) to make a paste. Rub the paste all over the pork and set on a rack and a small roasting pan. Roast until the thickest part of each tender loin registers 140*F on an instant-read thermometer, 25 to 35 minutes. Transfer to a clean cutting board to rest.
Meanwhile, peel the jicama and cut it into matchsticks about 4 incheslong and 1/4 inch thick. Cut the avocados in half, remove the pits and peel, and diagonally cut the flesh into thin slices. Slice the red onion half as thinly as possible. In a large bowl, gently combine the jicama, avocado, and red onion. Drizzle with the lime juice and remaining grapefruit juice and season to taste with salt and pepper. SLice the pork and divide it equally on dinner plates. Serve with the jicama salad.