Crab Casserole Florentine

Florentine is the kitchen shorthand for anything built on a bed of spinach, and this seafood version stacks that green base under two more layers of richness. Buttered chopped spinach gets cooked down hard to drive off every bit of liquid, then bound with cream of mushroom soup. That dryness is the whole game: wet spinach turns the casserole watery and the layers slump.

The top layer leans on a Swiss-cheese béchamel brightened with lemon juice, folded around picked-through crab meat and sliced water chestnuts. The chestnuts stay crisp under heat, which is the textural pop that keeps the dish from going one-note creamy.

A grated Parmesan lid browns into a salty, nutty crust during the long, low bake. Slow heat gives the layers time to merge without breaking the sauce or rubbering the crab.

Kitchen Tips

• Pick the crab carefully. Even canned lump crab hides shell fragments and cartilage; a quick spread on a white plate makes them easy to spot.
• Squeeze frozen spinach in a clean towel after thawing, even before it hits the butter. Less starting moisture means a faster, deeper sauté and better flavor.
• Warm the béchamel and stir the cheese in off the heat to keep the sauce from breaking. Swiss cheese splits if it boils.
• Let the casserole rest 10 minutes after baking. The layers firm up enough to scoop in tidy portions instead of soup.

Variations

• Use lump or jumbo lump crab from the seafood counter for a more luxurious texture and bigger crab presence.
• Swap the cream of mushroom for cream of celery and add a tablespoon of dry sherry to the béchamel for a classic seafood-Newburg twist.
• Stir a quarter teaspoon of grated nutmeg into the spinach layer for a deeper, more traditional Florentine flavor.