Sweet Potato Fries

These oven-baked low-FODMAP sweet potato fries stay under the 75g-per-serving mannitol limit and get their savory flavor from garlic-infused oil instead of garlic powder.

Prep 15 min

Cook 30 min

Serves 4

Gluten-freeDairy-freeVegan

Ingredients

• 300 g (about 2 medium) sweet potatoes, peeled. This gives four servings of roughly 75 g each.
• 1 tbsp cornstarch (cornflour), for a crisp coating
• 2 tbsp garlic-infused olive oil
• 1/2 tsp salt, plus more to finish
• 1/4 tsp smoked paprika
• 1/4 tsp ground cumin (optional)
• Freshly ground black pepper
• 1 to 2 scallion GREEN tops, thinly sliced, for garnish (optional; use the green part only)

Instructions

Cut and soak

1. Preheat the oven to 425°F (220°C) and line two baking sheets with parchment.
2. Cut the peeled sweet potatoes into batons about 1/4 inch (0.5 cm) thick so they cook evenly.
3. Soak the batons in a bowl of cold water for 20 to 30 minutes to draw out surface starch, then drain. Pat them very dry with a clean towel, since any leftover moisture steams the fries instead of crisping them.

Season

1. Put the dry fries in a large bowl and toss with the cornstarch until lightly and evenly coated.
2. Drizzle in the garlic-infused oil, then add the salt, smoked paprika, cumin if using, and a few grinds of pepper. Toss again so every piece is coated.

Bake

1. Spread the fries in a single layer across both sheets, leaving space between the pieces so they roast rather than steam.
2. Bake for 15 minutes, then flip each fry and rotate the pans. Bake another 10 to 15 minutes, until the edges are browned and crisp.
3. Let the fries rest on the pan for 5 minutes to firm up. Season with a little more salt, scatter the scallion greens over the top, and serve.

Tips & Substitutions

• Dry them thoroughly. Water on the surface is the main reason fries turn out soft, so pat them until no damp spots remain before seasoning.
• Cornstarch for crunch. A thin coat of cornstarch pulls moisture and builds a crisp shell. Rice flour or arrowroot work the same way if that is what you have.
• Do not crowd the pan. Two sheets with space around each fry beats one packed sheet every time. Crowded fries release steam and go limp.
• Air fryer version. Cook at 400°F (200°C) for 12 to 15 minutes, shaking the basket halfway through. Work in batches so the layer stays thin.
• Plain oil is fine. If you have no infused oil, use plain olive oil and lean on the paprika and cumin. Do not reach for a seasoning blend, since most hide onion or garlic powder.
• Mind the portion. The 75 g cap is per serving. Going back for a second helping stacks the mannitol, so plate the amount you want and put the rest away.

Why This Works

• Portion keeps mannitol in check. Sweet potato is low FODMAP at about 75 g (roughly 1/2 cup) per serving. Larger amounts move into the moderate range for mannitol, which is why the recipe is built around that weight.
• Garlic flavor without the fructans. Garlic-infused oil carries the aroma, but the fructans that trigger symptoms are water soluble and do not pass into the oil, so you get the taste without the FODMAP load.
• Cornstarch is a safe coating. Corn starch contains no fructans, lactose, or polyols, so it crisps the fries without adding FODMAPs.
• Whole spices, no hidden onion or garlic. Paprika, cumin, salt, and pepper season the fries directly, which sidesteps the onion and garlic powder baked into most commercial fry seasonings.

Storage

Cool leftovers, then refrigerate in an airtight container for up to 3 days. Reheat in a hot oven or air fryer for a few minutes to bring back the crisp, since the microwave leaves them soft. Keep each reheated portion to about 75 g to stay under the mannitol limit. These fries do not freeze well, as they turn mealy once thawed. Check the Monash app for current tested serving sizes if you are unsure about your portion.

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.