Slow-Simmered Senegalese Fish Yassa with Caramelized Onions

By , Test Kitchen Director · Reviewed by AislePrompt Editorial · ·

A tangy and savory Senegalese dish featuring marinated fish simmered in a rich onion and mustard sauce with lemon and chili heat. This african-inspired seafood ready in about 110 minutes pairs medium yellow onions, thinly sliced, garlic cloves, minced, fresh lemon juice for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 350 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.

Prep: 75 min Cook: 35 min Serves 4 African cuisine 350 cal/serving
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Ingredients

Instructions

  1. Step 1: Place 1 lb of firm white fish fillets into a shallow dish. Pour 1/4 cup fresh lemon juice, 2 tbsp Dijon mustard, 4 minced garlic cloves, 1 tsp salt, 1/2 tsp black pepper, and 1 tsp dried chili flakes over the fish. Marinate for at least 1 hour in the refrigerator to tenderize and infuse flavor.
  2. Step 2: Heat 3 tbsp vegetable oil in a large skillet over medium heat. Add 3 thinly sliced medium yellow onions and sauté for 12-15 minutes until deeply caramelized and golden brown, stirring occasionally to prevent burning.
  3. Step 3: Remove onions and set aside. In the same skillet, add the marinated fish along with 1 cup water and the caramelized onions. Cover and simmer gently over low heat for 15-20 minutes until the fish is cooked through and the sauce thickens slightly.
  4. Step 4: While the fish simmers, cook 2 cups uncooked white rice in 4 cups boiling salted water until tender, about 15 minutes, then drain.
  5. Step 5: Serve the fish yassa hot, spooning the tangy onion sauce over the rice for a complete Senegalese-inspired meal.

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Frequently asked questions

How long does Slow-Simmered Senegalese Fish Yassa with Caramelized Onions take to make?

Total time is about 110 minutes (75 min prep + 35 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Slow-Simmered Senegalese Fish Yassa with Caramelized Onions?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep garlic cloves, minced from drying out.

Can I substitute ingredients in Slow-Simmered Senegalese Fish Yassa with Caramelized Onions?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Slow-Simmered Senegalese Fish Yassa with Caramelized Onions for a different number of people?

The recipe is written for 4 servings. Multiply each ingredient by (your serving target / 4). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

What goes well with Slow-Simmered Senegalese Fish Yassa with Caramelized Onions?

African seafood like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.

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