You want a soup that tastes like a Michelin-level cheat meal but keeps you in ketosis? This is it. Tom Kha Gai is rich, tangy, creamy, and hits every corner of your taste buds like a combo move.
We’re talking restaurant flavor, zero bloat, and absolutely no sad salad energy. Ten ingredients, one pot, 30 minutes—your macros and your mouth both get a win. Make it once and you’ll “accidentally” make it every week.
Why This Recipe Works
This keto version of Tom Kha Gai keeps all the traditional flavor architecture—coconut creaminess, lemongrass brightness, galangal heat—while ditching the sugar landmines.
We use full-fat coconut milk for a silky base that’s naturally low-carb. A splash of fish sauce and fresh lime juice creates that sweet-salty-acidic trifecta you can’t fake. And by skipping palm sugar and rice noodles, you stay keto without sacrificing anything except the carb coma.
What You’ll Need (Ingredients)
- 2 cans (13.5 oz each) full-fat coconut milk
- 2 cups chicken broth (preferably low-sodium)
- 1 lb boneless, skinless chicken thighs, thinly sliced
- 1 stalk lemongrass, trimmed and smashed
- 4–6 slices galangal (or ginger if you must, but galangal is ideal)
- 4 kaffir lime leaves (tear in half to release oils)
- 8 oz mushrooms (oyster, shiitake, or button), sliced
- 2–3 Thai bird’s eye chilies, lightly crushed (adjust for heat)
- 2 tbsp fish sauce (or to taste)
- 2–3 tbsp fresh lime juice
- 1 tbsp avocado oil or coconut oil
- 1 small onion or 2 shallots, thinly sliced
- Fresh cilantro, chopped, for garnish
- Fresh Thai basil (optional), for garnish
- Sea salt and black pepper, to taste
- Optional keto boosters: 1 tsp erythritol or a few drops of monk fruit, 1 tsp red curry paste for extra depth
Step-by-Step Instructions
- Prep the aromatics. Smash the lemongrass with the back of a knife and cut into 2–3 pieces.
Slice galangal, tear kaffir lime leaves, and lightly crush the chilies. Keep everything chunky for easy removal later.
- Sauté the base. In a large pot, heat the oil over medium. Add onions or shallots and sauté 2–3 minutes until fragrant and translucent, not browned.
- Infuse the broth. Pour in chicken broth, then add lemongrass, galangal, lime leaves, and chilies.
Simmer gently for 8–10 minutes to extract maximum flavor without boiling aggressively.
- Add coconut milk. Lower heat and stir in the coconut milk. Keep it just below a simmer to prevent splitting. If using red curry paste, whisk it in now.
- Cook the chicken. Add sliced chicken thighs and mushrooms.
Simmer gently 8–10 minutes until chicken is cooked through and mushrooms are tender. Don’t boil—gentle heat keeps the soup silky.
- Season like a pro. Stir in fish sauce. Add lime juice gradually, tasting as you go.
Balance with a pinch of salt and pepper. If you miss a hint of sweetness, add erythritol or monk fruit sparingly.
- Finish and serve. Remove lemongrass, galangal, and lime leaves. Ladle into bowls and top with cilantro and Thai basil.
Optional: a final squeeze of lime and a few drops of fish sauce for the table.
Storage Tips
- Fridge: Store in an airtight container for up to 4 days. The flavors get even better by day two—yes, leftovers that flex.
- Freezer: Freeze up to 2 months. Thaw overnight in the fridge and reheat gently on low to keep the coconut milk from separating.
- Reheat: Low and slow.
Avoid boiling; it can break the coconut fat emulsion and make the soup look grainy.
What’s Great About This
- Keto without compromise: Creamy, aromatic, and satisfying with single-digit net carbs per serving, depending on mushrooms and onions used.
- Protein-forward: Chicken thighs bring flavor, satiety, and better texture than breasts. Gains-friendly, IMO.
- Flexible heat: Go mild or spicy. Your call, your sweat.
- Weeknight fast: One pot, minimal chopping, max payoff.
- Restaurant-level aroma: Lemongrass + galangal + kaffir lime = instant chef energy.
Common Mistakes to Avoid
- Boiling the coconut milk: This can cause splitting.
Keep the heat below a simmer after adding coconut milk.
- Skipping the aromatics: Substituting everything with lime juice and ginger won’t deliver the same complexity. If possible, source lemongrass and kaffir lime leaves.
- Overcooking chicken: Thin slices cook fast. Check at 8 minutes and pull from heat as soon as it’s opaque and tender.
- Under-seasoning: Tom Kha is about balance—salty, sour, creamy, and lightly sweet.
Taste repeatedly at the end and adjust.
- Using light coconut milk: It’s watery and sad. Full-fat only for this vibe.
Recipe Variations
- Tom Kha Shrimp: Swap chicken for peeled shrimp. Add shrimp in the last 3–4 minutes so they don’t turn rubbery.
- Extra Veggie Keto: Add zucchini ribbons, baby bok choy, or spinach in the final 2 minutes.
Low-carb bulk, zero boredom.
- Mushroom-Heavy: Use a mix of shiitake, oyster, and enoki for mega umami. Great for a lighter protein day.
- Spice Storm: Add 1–2 tsp red curry paste or a few drops of chili oil. Respect the heat.
- Collagen Boost: Use bone broth instead of chicken broth for extra protein and richness.
- Dairy-Style Creaminess (still dairy-free): Stir in 1 tsp coconut cream at the end for an ultra-luxe finish.
FAQ
Can I make this without galangal?
Yes, use fresh ginger as a stand-in, but note the flavor shifts slightly sweeter and less citrusy.
If you can find galangal at an Asian market or online, it’s worth it for the authentic bite and aroma.
Is fish sauce necessary?
It brings essential umami and salt. If you must skip it, use extra salt plus a splash of coconut aminos (watch carbs) to mimic some depth, but the flavor won’t be identical.
How do I keep it keto if I want a touch of sweetness?
Use erythritol or monk fruit sweetener—start with 1/2 teaspoon and taste. Traditional versions often include a bit of palm sugar, but keto-friendly sweeteners keep you on track.
Can I use chicken breast instead of thighs?
Yes, slice thin and add near the end to avoid dryness.
Thighs are more forgiving and stay tender even if you forget and let it simmer a minute too long (happens to the best of us).
What can I serve with this on keto?
Shirataki noodles, zucchini noodles, or cauliflower rice work great. Keep portions modest so the soup remains the star player.
Why did my soup separate?
It likely boiled after adding coconut milk. Reheat gently and whisk; it’ll still taste fantastic even if the texture isn’t picture-perfect.
Next time, keep the heat just below a simmer.
How spicy is this?
Totally user-defined. Start with one chili for mild, two for medium, three for “I can handle it,” and more if you’ve got something to prove.
The Bottom Line
Keto Thai Coconut Soup (Tom Kha Gai) proves you can eat like a foodie and still crush your macros. It’s fast, fragrant, and ridiculously comforting—perfect for busy nights or impressing guests without breaking a sweat.
Stock a few key aromatics and you’ve got a repeatable, restaurant-quality soup on command. File this under “minimum effort, maximum flex,” because that’s exactly what it delivers.
Printable Recipe Card
Want just the essential recipe details without scrolling through the article? Get our printable recipe card with just the ingredients and instructions.
Andreas – Keto recipe creator who lost 40lbs and discovered his love for low-carb cooking. 300+ tested recipes | 5 years of keto experience | Real food for real people. No certifications, just results that taste amazing!