Preheat oven to 375°. Spray a small rimmed baking pan with nonstick spray. Pat cod fillets dry with paper towels; place in prepared pan. Sprinkle with 1 tsp. Cajun seasoning. Bake for 12 to 18 minutes or until fish flakes easily with a fork (145°). Set aside.

Meanwhile, heat olive oil in a large Dutch oven over medium heat. Add spinach and garlic; cook for 1 to 2 minutes or until spinach is wilted, stirring constantly. Set aside to cool slightly.

Whisk together Alfredo sauce, half-and-half, remaining 2 tsp. Cajun seasoning and shrimp & crab boil in a large bowl until smooth. Set aside.

Coarsely shred crabmeat pieces, then coarsely chop into ½-in. pieces. Place in another large bowl. Flake cooked cod into 1-in. pieces; add to bowl. Add lemon juice; toss to coat and set aside.

Stir together egg and ricotta cheese in medium bowl. Stir in 1 c. Italian cheese and Parmesan cheese.

Spray a 13x9-in. baking dish with nonstick spray. Spread ¾ c. Alfredo sauce mixture in bottom of the prepared baking dish. Top with 4 uncooked lasagna noodles, breaking noodles as necessary to cover. Layer with 1 c. ricotta mixture, 1½ c. crabmeat mixture, ¾ c. sauce mixture and half of spinach mixture. Repeat layers 2 more times using noodles, ricotta mixture, crabmeat mixture and sauce mixture. Top with remaining half of spinach mixture and remaining lasagna noodles. Gently press down on noodles to compact layers. Spread remaining sauce evenly to completely cover noodles.

Tightly cover baking dish with foil; place on a large baking sheet. Bake for 40 minutes. Remove foil; sprinkle with remaining 1 c. Italian cheese. Bake for 15 to 20 minutes or until bubbly and lightly browned. Remove from oven; let stand 15 minutes before cutting. Garnish with chives and additional Cajun seasoning, if desired.