- 1 (2 pound) pork tenderloin, trimmed of fat
- 1 teaspoon chili powder
- 1 teaspoon garlic powder
- 1/2 teaspoon paprika
- 1/4 cup sweet and sour sauce (such as Kikkoman®), or as needed
- 3 tablespoons honey
- 4 teaspoons prepared yellow mustard
- 2 cups water, or as needed
- Rinse pork tenderloin with cold water, pat dry, and place in a baking dish.
- Whisk chili powder, garlic powder, and paprika together in a bowl. Rub mixture all over pork tenderloin until completely covered. Cover baking dish with aluminum foil and refrigerate for 24 hours.
- Preheat oven to 300 degrees F (150 degrees C).
- Brush a thin coat of sweet and sour sauce all over tenderloin and let rest for 10 minutes.
- Whisk honey and mustard together in a bowl. Brush a heavy coat of honey mustard onto the tenderloin. Pour water into the baking dish to reach a depth of 1/2-inch. Cover the baking dish with aluminum foil.
- Cook until pork is slightly pink in the center, about 1 1/2 hours. An instant-read thermometer inserted into the center should read at least 145 degrees F (63 degrees C).