1.
In large bowl, combine chili powder, paprika, cumin, salt, white pepper, garlic, orange juice, orange peel, lime juice and hot pepper sauce; mix well. Reserve 1/4 cup marinade.
1.
Freeze pork 10 - 12 minutes or until firm and easy to cut; cut into 3/4-Inch cubes. Add pork and onion to marinade; turn to coat. Marinate 4 hours, covered in refrigerator. Remove pork from marinade; discard marinade. Thread skewers with pork and onion using 3 cubes pork per skewer.
2.
Heat a charcoal grill to medium heat. Cook skewers until pork is firm, cooked through and internal temperature reaches 160°F. Alternately, skewers may be baked in a 475°F oven 12 - 15 minutes, basting with reserved marinade every few minutes.
3.
Place pork on serving platter; serve hot or at room temperature along with Creamy Pumpkin Sauce. Garnish platter with cilantro.
For Creamy Pumpkin Seed Sauce:
1.
Heat oven to 350°F. Place pumpkin seeds on baking sheet; toast 20 minutes, shaking frequently after 10 minutes to prevent burning. Remove from oven; cool.
2.
Place seeds in blender or food processor; purée with chipotle and tomatoes, scraping down container as needed. Add water and lime juice to blender; process until mixed. Add oil and salt; process until creamy sauce forms.
3.
Transfer sauce to medium bowl. Gently stir in green onions and cilantro.