Pan-Seared Lake Superior Whitefish with Mashed Potatoes and Cole Slaw

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-06-27 · Updated 2026-06-27

A classic Upper Peninsula dish featuring fresh Lake Superior whitefish pan-seared to golden perfection, served with creamy mashed potatoes and tangy homemade cole slaw. This american-inspired seafood ready in about 45 minutes pairs unsalted butter, olive oil, salt for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 480 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 4 fillets (6 oz each) Lake Superior whitefish fillets
• 3 tbsp unsalted butter
• 2 tbsp olive oil
• 1 tsp salt
• 1/2 tsp black pepper
• 2 lbs, peeled and quartered russet potatoes
• 3/4 cup whole milk
• 1/4 cup sour cream
• 3 cups shredded green cabbage
• 1 medium, shredded carrot
• 2 tbsp apple cider vinegar
• 1 tbsp granulated sugar
• 1/2 tsp celery seed
• 1/3 cup mayonnaise
• 1/2 tsp salt (for cole slaw)
• 1/4 tsp black pepper (for cole slaw)

Instructions

1. Step 1: Place 2 lbs peeled and quartered russet potatoes in a large pot and cover with cold water. Add 1 tsp salt and bring to a boil over high heat. Cook for 15-18 minutes until potatoes are tender when pierced with a fork, then drain.
2. Step 2: While potatoes cook, heat 2 tbsp olive oil and 3 tbsp unsalted butter in a large non-stick skillet over medium-high heat. Season 4 Lake Superior whitefish fillets evenly with 1 tsp salt and 1/2 tsp black pepper. Sear the fillets skin-side down for 4 minutes until the skin is golden and crisp, then flip and cook for another 2-3 minutes until the fish flakes easily.
3. Step 3: Return the drained potatoes to the pot off heat. Add 3/4 cup whole milk and 1/4 cup sour cream, then mash with a potato masher until smooth and creamy. Adjust seasoning with salt and pepper to taste.
4. Step 4: In a medium bowl, combine 3 cups shredded green cabbage, 1 shredded medium carrot, 1/3 cup mayonnaise, 2 tbsp apple cider vinegar, 1 tbsp granulated sugar, 1/2 tsp celery seed, 1/2 tsp salt, and 1/4 tsp black pepper. Toss well until the cabbage is coated and the dressing is evenly distributed.
5. Step 5: Plate each whitefish fillet alongside a generous scoop of mashed potatoes and a serving of the tangy cole slaw. Serve immediately while warm.