Spiced Senegalese Fish Yassa with Caramelized Onions and Mustard Sauce

By AislePrompt Editorial · Published 2026-06-11 · Updated 2026-06-11

How this recipe was made — this recipe was drafted by AislePrompt's AI-assisted pipeline from technique templates and USDA-sourced nutrition data, and published by AislePrompt Editorial — see how AislePrompt recipes are drafted and published.

Fish fillets marinated in a vibrant mustard-lemon sauce, then pan-seared and served atop a bed of slowly caramelized onions packed with Senegalese spices. This African-inspired seafood recipe, ready in about 40 minutes, pairs yellow onions, thinly sliced, fresh lemon juice, Dijon mustard for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 320 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: 10 min Cook: 30 min Serves 4 African cuisine 320 cal/serving

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Ingredients

4 pieces (about 1.5 lbs) white fish fillets (such as tilapia or snapper)
2 large yellow onions, thinly sliced
1/3 cup fresh lemon juice
3 tbsp Dijon mustard
3 garlic cloves, minced
4 tbsp vegetable oil
1 1/2 tsp salt
1 tsp black pepper
1/2 tsp smoked paprika
1 small scotch bonnet pepper, finely chopped (optional)

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Instructions

Step 1: In a bowl, whisk together 1/3 cup fresh lemon juice, 3 tbsp Dijon mustard, 3 minced garlic cloves, 1 1/2 tsp salt, 1 tsp black pepper, and 1/2 tsp smoked paprika. Add 4 white fish fillets and coat them thoroughly. Marinate for 30 minutes.
Step 2: Heat 3 tbsp vegetable oil in a large skillet over medium heat. Add 2 large thinly sliced yellow onions and 1 finely chopped scotch bonnet pepper (optional). Cook for 15 minutes, stirring occasionally, until onions are deeply caramelized and soft.
Step 3: Remove onions from skillet and set aside. Add 1 tbsp vegetable oil to the same skillet and heat over medium-high heat. Add marinated fish fillets and sear for 4-5 minutes per side until golden and cooked through.
Step 4: Serve fish fillets on a bed of the caramelized onions, spooning any pan juices over the top for added flavor.