Fish Tacos

INGREDIENTS

• 1/2 red onion, thinly sliced
• About 1 1/2 cups red wine vinegar
• 1/4 cup olive oil
• 1 1/2 teaspoons ancho chile powder
• 1 1/2 teaspoons dried oregano
• 1/2 teaspoon ground cumin
• 1/4 cup lightly packed fresh cilantro leaves, chopped, plus more for garnish
• 1 jalapeño, stemmed and chopped
• 1 pound flaky white fish (such as mahi mahi or cod), cut into 4 pieces
• Salt
• 8 fresh corn tortillas
• Mexican crema, homemade or store-bought
• Fresh Tomato Salsa
• 2 limes, cut into quarters