Caramelized Onions with Patis (Filipino Fish Sauce)

Patis Caramelized Onions are gourmet-style onions finished with the savory, umami depth of Filipino fish sauce. This versatile condiment comes together quickly and elevates burgers, sandwiches, pizzas, and more.

With just 4 simple ingredients, this recipe is easy to make at home.

Traditional caramelized onions can take up to two hours, but this method delivers rich, complex flavor in a fraction of the time — typically 25–40 minutes.

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Table of Contents

What is Patis?

Patis is a Filipino fish sauce produced as a liquid byproduct of bagoong (shrimp paste) production. It’s widely used in Filipino cooking to add salty, savory, and umami notes to dishes. Patis varies between brands in saltiness and pungency, so start conservatively — about 1–2 tablespoons — and adjust to taste.

How these onions are prepared

Caramelizing onions depends on drawing out moisture and concentrating their natural sugars. In this recipe patis replaces plain salt, contributing both the salting effect and additional umami complexity. The technique uses a brief steaming step to soften the onions quickly, then finishes with browning for deep color and flavor.

Tips & tricks

Make caramelized onions faster and more reliably with these tips:

• Steam briefly to soften.
  • Add a small amount of water, cover, and steam for 5–10 minutes until the onions are fully softened. This cuts down the initial cooking time compared to the classic low-and-slow approach.
• Choose the right pan.
  • Stainless steel or cast iron heats evenly and encourages browning. Nonstick pans make cleanup easier but may take longer to develop deep caramelization.
• Brown without burning.
  • Spread the onions in an even layer and let them sit to develop color. Stir occasionally to prevent burning. Deglazing with a splash of water lifts flavorful browned bits from the pan and reincorporates them into the onions.

Serving suggestions

Patis Caramelized Onions add savory depth to many dishes. Try them:

• On burgers
• Over loaded fries
• On hot dogs
• As a topping for BBQ pizza
• Inside sandwiches and wraps
• In savory tarts and pastries

They also work beautifully in Filipino-inspired recipes like onion tarts paired with Eden cheese. Use them anywhere you’d like a rich, savory boost.

Equipment

• A heavy-bottomed pan such as stainless steel or cast iron
• Sharp knife and cutting board

Ingredients

• 3 large yellow onions
• 3 tbsp unsalted butter
• 2 tbsp patis (Filipino fish sauce), adjust to taste
• Black pepper, to taste

Recipe

1. Peel and slice the onions into half-moon strips.
2. Place the sliced onions in a pan and add enough water to reach about 1/4 inch deep.
3. Cover and turn the heat to high. Steam for about 10 minutes, until the onions are softened.
4. Remove the lid, add the butter and patis, and lower the heat to medium-high.
5. Cook with the lid off, stirring to distribute the butter and fish sauce. Allow the liquid to evaporate, then spread the onions into an even layer to encourage browning.
6. Let the onions brown, stirring only to prevent scorching — roughly every 2 minutes — for 20–30 minutes until they reach the desired color.
7. If bits begin sticking, deglaze the pan with a splash of water, scraping up the caramelized fond and mixing it back into the onions. Continue until you reach a light or deep brown, depending on your preference.

Final thoughts

These patis-infused caramelized onions are a quick way to add Filipino-inspired umami to your cooking. They store well in the fridge and make a flavorful condiment to keep on hand for sandwiches, pizzas, and more. Adjust the patis to suit your salt preference and enjoy a rich, savory topping with minimal fuss.

If you make this recipe, consider leaving a rating and sharing your results — we’d love to see how you use them!