can artichoke hearts, chopped 2 c. frozen spinach, defrosted and chopped Juice of 1/2 a lemon 1/2 tsp. frozen cheese ravioli Kosher salt Freshly ground black pepper 2 tbsp. Fold in artichoke hearts and spinach, then add lemon juice and red pepper flakes, if using, and season to taste with salt and pepper. Repeat with remaining ravioli and remaining sauce. Top with remaining cheese and bake 30 minutes, until sauce is bubbling and ravioli are tender.