Heat grill to high. Brush pork with oil and season with salt, pepper, and cumin, to taste. Grill for 3 to 4 minutes.
Turn the tenderloins over and brush with guava glaze and cook another 4 to 5 minutes, brushing with the glaze every few minutes. Remove from the grill, brush with more of the glaze and let rest for 10 minutes. Slice into 1/2-inch thick slices and drizzle with the Orange-Habanero Mojo. Garnish with mint sprigs.
For the Guava Glaze:
Whisk together ingredients in a small bowl and season with salt and pepper, to taste.
For the Orange-Habanero Mojo:
In a saucepan, combine citrus juices, onion, garlic, habanero, and cumin.
Cook over medium heat until reduced by 1/2 and season with salt and pepper, to taste. Strain.