Fish Tacos

These low-FODMAP fish tacos pile spice-rubbed white fish and a lime cabbage slaw into warm corn tortillas, using garlic-infused oil and scallion green tops in place of onion and garlic.

Prep 20 min

Cook 10 min

Serves 4

Gluten-freeDairy-free

Ingredients

Fish and spice rub

• 1 lb (450 g) firm white fish fillets, such as cod, haddock, or mahi mahi
• 2 tsp ground cumin
• 1 tsp smoked paprika
• 1/2 tsp ground coriander
• 1/4 to 1/2 tsp pure ground chili (ancho, chipotle, or cayenne), see the note below
• 1/2 tsp salt
• 2 tbsp garlic-infused olive oil, divided
• Zest and juice of 1 lime

Cabbage slaw

• 3 cups (about 225 g) shredded common green or red cabbage (about 56 g per serving, under the 75 g cap)
• 1 medium carrot (about 60 g), grated
• 2 scallions, green tops only, thinly sliced
• 1/3 cup (75 g) mayonnaise
• 2 tbsp lime juice
• 1 tbsp garlic-infused olive oil
• Small handful cilantro, chopped
• Salt, to taste

To serve

• 8 small plain corn tortillas (check the Monash app for your tested serving size)
• 1/4 ripe avocado, thinly sliced (keep to about 30 g per person)
• Lime wedges
• Extra cilantro

Instructions

Make the slaw

1. In a large bowl, whisk the mayonnaise, lime juice, and 1 tbsp garlic-infused oil until smooth.
2. Add the shredded cabbage, grated carrot, scallion green tops, and cilantro. Toss to coat.
3. Season with salt to taste, then set aside so the cabbage softens slightly while you cook the fish.

Season and cook the fish

1. Pat the fish dry. In a small bowl, combine the cumin, smoked paprika, coriander, ground chili, and salt. Rub the mixture over both sides of the fillets, then add the lime zest.
2. Heat 1 tbsp garlic-infused oil in a large skillet over medium-high heat. Add the fish and cook 3 to 4 minutes per side, depending on thickness, until the flesh is opaque and flakes easily.
3. Cook fish to an internal temperature of 145 F (63 C). Squeeze the fresh lime juice over the top, then break the fillets into large chunks with a fork.

Warm the tortillas and assemble

1. Warm the corn tortillas one at a time in a dry skillet for about 20 seconds per side, or wrap the stack in a damp towel and microwave for 30 seconds.
2. Divide the slaw among the tortillas, then top with chunks of fish.
3. Finish with a few avocado slices, extra cilantro, and a squeeze of lime.

Tips & Substitutions

• Skip chili powder blends. Most jarred "chili powder" and taco seasoning packets contain onion and garlic powder. Use a single ground chili such as ancho or cayenne, plus the cumin and paprika in the rub.
• Frozen fish is fine. Thaw firm white fillets fully and pat them very dry so the rub sticks and the fish sears instead of steaming.
• Add a creamy dressing. For a tangier slaw, swap half the mayonnaise for lactose-free plain yogurt. That version is no longer dairy-free, so keep the mayo base if you need to avoid dairy.
• Watch the cabbage portion. Common green and red cabbage are low FODMAP up to 75 g per serving. Savoy cabbage has a smaller safe serve, so stick with common or red here.
• Cap the avocado. Avocado is low FODMAP at about 30 g, roughly a few thin slices. Add more lime and cilantro instead of a heavier scoop.
• Make your own garlic oil. Homemade garlic-infused olive oil gives you the garlic flavor without fructans, since fructans are not oil-soluble.

Why This Works

• Garlic-infused oil carries the flavor. Fructans, the FODMAP in garlic, do not dissolve into oil, so infused oil delivers garlic taste in both the rub and the slaw without the trigger.
• Scallion green tops replace onion. The green tops of scallions are low FODMAP, while the white bulbs are not. They add fresh onion flavor to the slaw safely.
• Cabbage stays within a tested serve. Splitting about 225 g of cabbage across four servings keeps each portion near 56 g, comfortably under the 75 g cap for common cabbage.
• Corn tortillas keep it gluten-free. Plain corn tortillas are naturally free of wheat and its fructans, unlike flour tortillas, which makes them a reliable low-FODMAP base.

Storage

Store the cooked fish and slaw in separate airtight containers in the fridge for up to 2 days. Keep tortillas wrapped at room temperature or in the fridge and warm them fresh. Reheat the fish gently in a skillet or microwave just until warmed through, since white fish overcooks quickly. Assemble tacos only when you are ready to eat so the tortillas and slaw stay crisp.

Not sure about an ingredient? The FODMAP Foods app rates 1,000+ foods low, moderate, or high FODMAP, with the safe portion for each, so you can cook with confidence.