Instructions

1. 1
   In a large bowl, combine the sliced onions, lemon juice, vegetable oil, Dijon mustard, minced garlic, thyme leaves, paprika, black pepper, and salt to make a marinade.
2. 2
   Add the chicken or fish pieces to the marinade and mix well to ensure they are evenly coated. Cover the bowl and refrigerate for at least 2 hours, or preferably overnight, to allow the flavors to develop.
3. 3
   Remove the chicken or fish from the marinade, reserving the marinade for later use.
4. 4
   Heat a large skillet over medium-high heat. Add the chicken or fish to the hot skillet and cook until browned on all sides and cooked through. Remove from the pan and set aside.
5. 5
   In the same skillet, add the sliced onions from the marinade and sauté until they become soft and translucent.
6. 6
   Return the cooked chicken or fish to the skillet with the sautéed onions. Pour the reserved marinade over the meat and onions. Reduce the heat to low and let the mixture simmer for about 15–20 minutes, allowing the flavors to meld together.
7. 7
   Taste and adjust the seasoning with salt and pepper if needed.
8. 8
   Serve hot with steamed rice, couscous, or bread.