Proteins

Flounder (Hirame)

Mild lean flatfish, sliced thin as hirame sashimi or pan-fried whole.

Flounder is a lean, mild-flavored flatfish with delicate white flesh. In Japan, hirame is sliced thin for sashimi and prized for its subtle sweetness and firm bite, while in the West it is pan-fried, baked, or stuffed. Its thinness makes it cook quickly and pair well with light sauces.

Flounder refers to several species of flatfish prized for their exceptionally mild, clean-flavored flesh. In Japanese cuisine, the fish is called hirame (Paralichthys olivaceus), while North American varieties include summer flounder, also known as fluke (Paralichthys dentatus), and winter flounder or blackback (Pseudopleuronectes americanus). The fish has a distinct flat body, with both eyes on one side, and is caught wild or farmed across the North Pacific and Atlantic coasts.

What makes flounder remarkable in the kitchen is its combination of delicacy and versatility. The flesh is snow-white, firm yet tender, and flakes easily with the gentlest pressure. Its extremely low fat content (1–2%) means the flavor is clean and subtle—no fishy edge when fresh—but also that the fish demands respect: overcooking turns it dry and mushy almost instantly. This is a fish that rewards attentive cooking and restraint in seasoning, making it a canvas for technique rather than a vehicle for bold flavors.

In Japanese kitchens, hirame is considered a premium sashimi fish, prized alongside tai (sea bream) for its natural sweetness and silky texture when sliced paper-thin. In European and American traditions, flounder excels in classic preparations like meunière, pan-frying whole, or in delicate poached preparations. The challenge for home cooks is accessing truly fresh fish and understanding its narrow window of optimal doneness—less than a minute for most cooking methods.

Measured in: g
Storage: Fridge

Allergens

Fish

Types & varieties

Hirame (Japanese Flounder)

The premium variety; farmed and wild; prized for sashimi in Japanese cuisine; sweeter and more delicately flavored than Atlantic varieties

Summer Flounder (Fluke)

Paralichthys dentatus; US East Coast; lean, mild; slightly sweeter than winter flounder; excellent raw or pan-fried

Winter Flounder (Blackback)

Pseudopleuronectes americanus; Atlantic coast; firmer texture; mild flavor; traditionally used in New England chowders and fried preparations

Dover Sole

Microstomus kitt; a true sole from Eastern Atlantic waters; mild, fine-textured; excellent for meunière preparation

Plaice

North Atlantic flatfish; similar mild flavor; often sold skin-on; good for pan-frying whole

Selecting and Assessing Freshness

Because flounder's flavor is so restrained, any decline in freshness becomes immediately apparent. Smell alone is not reliable for this mild fish—the signs of quality are found elsewhere. Fresh flounder should have clear, convex eyes that bulge slightly; dull or sunken eyes indicate age. The gills should be bright red or pink, not brown or gray. The flesh should spring back when pressed and should not have a slimy or mushy texture. For sashimi use, buy whole fish when possible and request the fishmonger kill it by ikejime (spiking the brain), which dramatically improves texture and extends the usable window by preserving cellular integrity. Never buy flounder for raw service that has been sitting on ice for more than a few hours after death.

Clear, bulging eyes indicate freshness
Bright red or pink gills—not brown or gray
Flesh springs back when pressed gently
Request ikejime killing for sashimi-grade fish
Avoid fish with any sour or ammonia-like odor

Filleting Flounder

Flounder filleting requires a sharp, flexible knife and patience. The skin adheres tightly to the flesh, particularly on farmed hirame, and the bones run along the centerline. Work from tail toward head, keeping the blade nearly parallel to the backbone to maximize yield. For the skin-side down fillet (the cleaner of the two), slide the blade between skin and flesh at the tail end, then grip the skin with a cloth and draw the knife forward at a slight angle while maintaining downward pressure on the blade. If the skin resists, salt it lightly and let it rest for 5 minutes—the flesh will release cleanly. Remove pin bones with fish tweezers before cooking. With practice, expect 35–45% yield to skin-on fillet from a whole fish.

Use a sharp, flexible filleting knife
Work tail-to-head with blade nearly parallel to bones
Salt the skin 5 minutes before peeling for easier removal
Remove pin bones with fish tweezers before cooking
Expect 35–45% yield from whole to skin-on fillet

Common uses

Sashimi and sushi—hirame is a classic Edo-style sashimi fish; sliced paper-thin against the grainCrudo or carpaccio—dressed with olive oil, lemon, sea salt, and chivesPan-frying whole (European style)—dredged in flour, finished with brown butter and capersGrilling—lightly oiled whole fish or thick fillets over medium-high heatPoaching in white wine and aromatics for a gentle, moist preparationSteaming (Chinese style) with ginger, scallion, and light soyFish tacos—flaked cooked flounder with slaw and cremaBeurre blanc or light cream sauces to complement without overwhelmingFish stock—the lean bones and trimmings make a clean, mild base

Tips & pitfalls

Buy from a trusted fishmonger; flounder's mild flavor means any lack of freshness is immediately obvious
For sashimi, request ikejime killing—this dramatically improves texture and shelf life
When filleting, work from the tail toward the head with the blade nearly parallel to the bones to maximize yield
Salt the skin lightly and let it sit 5 minutes before peeling—the flesh will release cleanly
Do not overcook: flounder turns dry and mushy in under a minute at high heat; pull it from the pan the moment it turns opaque
If pan-frying whole, score the flesh 3–4 times to the bone to prevent curling and ensure even cooking
For a crispier crust when pan-frying fillets, pat them completely dry and let them rest uncovered in the refrigerator for 30 minutes before cooking
Use flounder the day of purchase if serving raw; smell is not always a reliable indicator of freshness for mild fish—check the gills and eyes instead

Nutrition

70kcal

Energy

293 kJ · per 100 g

Where the calories come from

Protein 74%Carbs 0%Fat 26%

Protein

12.4g

25% DV

Carbs

0% DV

Fat

1.9g

2% DV

Fiber

0% DV

Sugars

of which

Sodium

296mg

13% DV

Notable micronutrients

Selenium48% DV

Vitamin B1247% DV

Phosphorus20% DV

Vitamin D14% DV

Niacin (B3)7% DV

Vitamin B66% DV

Source · USDA FoodData Central · Fish, flatfish (flounder and sole species), raw

View on FDC →

In the shops

Matched grocery products

No matched grocery products for Flounder (Hirame) yet.

Good to know

Scientific Name: Paralichthys olivaceus (Japanese hirame); P. dentatus (summer flounder); Pseudopleuronectes americanus (winter flounder)
Origin: North Pacific (Japan, Korea, China) and Atlantic coasts of North America
Peak Season: December–February (winter; hirame is considered a cold-season fish in Japan)
Flavor: Mild, subtly sweet, clean briny taste with no fishy edge when fresh
Texture: Firm but delicate; flesh flakes easily; snow-white when cooked
Fat Content: Very low (1–2%); classified as a lean fish
Yield: 35–45% from whole to skin-on fillet; 30–35% to skinless
Shelf Life: 1–2 days raw; cook same day for sashimi use

Substitutes

Dover Sole — Nearly identical texture and mildness; slightly nuttier flavor; best substitute for European preparations
Brancacio (Sea Bass) — Firm, mild white fish; holds up better to grilling; less delicate than flounder but a valid substitute
Halibut — Lean and mild but denser; requires slightly longer cooking; works for pan-frying and grilling
Red Snapper — Slightly firmer and mildly sweet; works in most applications but not ideal for raw preparations
Plaice — Very similar mild flavor and texture; can be used interchangeably in most cooked applications
Turbot — Premium substitute; firm but delicate; excellent for pan-frying whole or as a refined sashimi fish