Grilled Spice-Rubbed Tuna w/ Avocado-Corn Vinaigrette

four fresh 8 oz. tuna steaks

For rub:
2 T. ground cumin   
2 T. ground coriander
1/4 C. paprika   
1/4 C. packed brown sugar
salt & freshly cracked black pepper

Vinaigrette:
3/4 C. olive oil   
1/4 C. lime juice
1/4 C. red wine vinegar
4 cloves garlic, peeled
1 T. minced Poblano chili
one ear corn, husked, desilked, blanched in boiling water (2 min.), kernel cut off cob
one avocado, peeled & pitted
salt & freshly cracked black pepper

Puree corn, avocado, garlic & poblano in food processor until smooth. With processor still running, slowly drizzle in oil. Add remaining ingredients. Pulse to mix. In a small bowl, mix rub ingredients and rub steaks generously with mix. Place on grill over medium-low fire. Cook three minutes on each side. Serve hot off grill, drizzled with chilled vinaigrette. Garnish with lime wedges and fresh cilantro.