Preheat oven to 450 F.

Wash and dry green bell peppers, yellow bell peppers and lime.

Trim, seed and slice bell peppers lengthwise into thin strips; transfer to large baking sheet.

Peel, halve and slice onion lengthwise into thin pieces; add to baking sheet with bell peppers.

Drizzle veggies with oil, toss to combine and spread in even layer. Bake until veggies have softened slightly, about 5 minutes.

If using frozen shrimp, place them in colander and run under cold water to thaw slightly. Place shrimp on clean towel or paper towels and pat dry.

Remove baking sheet from oven. Arrange shrimp over veggies then sprinkle with 4 teaspoons Cajun seasoning and salt; toss to combine and spread in even layer.

Bake until veggies are tender and shrimp are cooked through, 5-7 minutes. Remove from oven.

Cut lime into wedges.

In small bowl, stir ranch dressing and remaining Cajun seasoning.

Warm tortillas in skillet, oven or microwave, if desired.

Divide tortillas between plates and fill with shrimp and veggies; drizzle with spicy ranch and serve with squeeze of lime.