Toast corn tortillas on a hot griddle on both sides, about 1-2 minutes each. Set aside.
Season chicken tenders with 1 teaspoon salt and cumin.
Add 1 tablespoon olive oil to a large skillet and place over medium-high heat. Add chicken tenders and cook for about 4 minutes per side or until cooked through and browned. Set aside.
Add remaining 1 tablespoon of oil to skillet, add onions, poblano pepper, and garlic to skillet. Season with 1 teaspoon salt. Cook, stirring often until onions are translucent, about 5 minutes. Stir in salsa and 1 tablespoon of lime juice. Lower to simmer and cook about 3 minutes. Remove from heat.
Toss prepared couscous with 2 tablespoons of lime juice and 1 tablespoon cilantro.
Spread couscous mixture over toasted corn tortillas and place on a baking sheet. Layer sliced chicken over couscous and top with salsa mixture. Sprinkle generously with cheese. Place under broiler for about 2 minutes or until cheese is melted and bubbly.
Garnish with sour cream and cilantro.
Serve immediately.