Equipment
Ingredients
Sauce Base
- 225 g unsalted butter, chilled
- 100 g red onion, thinly sliced
- 2 garlic, thinly sliced
- 8 shiitake mushroom stems
- 75 g tomato, coarsely chopped
- 1 bay leaf
- 6 g black peppercorns
- 80 ml balsamic vinegar
- 80 ml water
- 1 g salt, to taste
- 1 g black pepper, to taste
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 221 kcal
- Protein
- 1 g
- Carbohydrates
- 4 g
- Fat
- 23 g
- Fiber
- 1 g
- Sugar
- 2 g
- Sodium
- 56 mg
- Saturated Fat
- 14 g
- Monounsaturated Fat
- 7 g
- Polyunsaturated Fat
- 1 g
- Cholesterol
- 60 mg
- Potassium
- 82 mg
- Calcium
- 19 mg
- Iron
- 0.2 mg
- Magnesium
- 6 mg
- Phosphorus
- 20 mg
- Zinc
- 0.1 mg
- Vitamin A
- 197 mcg
- Vitamin C
- 2 mg
- Vitamin D
- 0.0 mcg
- Vitamin E
- 0.7 mg
- Vitamin K
- 4 mcg
- Vitamin B6
- 0.0 mg
- Vitamin B12
- 0.1 mcg
- Thiamin
- 0.02 mg
- Riboflavin
- 0.02 mg
- Niacin
- 0.2 mg
- Folate
- 5 mcg
- Water
- 45 g
Sources: USDA FoodData Central
Method
Melt 25g of the butter in a large saucepan over medium heat.
Add the sliced red onion, garlic, shiitake stems, chopped tomato, bay leaf, and peppercorns to the pan. Sauté for 6 minutes until the vegetables are soft but not browned.
Pour in the balsamic vinegar and water. Increase the heat to medium-high and simmer for approximately 8 minutes until the liquid reduces to a syrupy consistency.
Lower the heat. Gradually whisk in the remaining 200g of cold butter a few pieces at a time, ensuring each addition is fully emulsified before adding more.
Pass the sauce through a fine sieve into a clean container to remove solids. Season with salt and black pepper to taste.
Keep the sauce warm over a double boiler (approx 50-60°C / 122-140°F) until ready to serve.
Chef's Notes
- Using cold butter is essential for a stable emulsion; softened butter will melt into oil too quickly.
- Shiitake stems provide deep umami but are discarded after straining.
Storage
Refrigerator: 72 hours — Sauce may separate when chilled; must be gently reheated.
Reheating: Warm gently over a double boiler while whisking to maintain the emulsion.
Troubleshooting
Sauce is oily and separated
Cause: The temperature was too high during butter addition or butter was added too fast.
Fix: Whisk in a teaspoon of warm water or heavy cream to re-bind the emulsion.
Prevention: Ensure butter is cold and added gradually while whisking over low heat.
Cultural Context
While balsamic vinegar originates from Modena, Italy, this reduction technique of concentrating its flavor is a staple in French haute cuisine. It's often used to add a sophisticated, tangy depth to classic dishes like pan-seared duck breast or roasted meats, showcasing a fusion of Italian ingredient and French culinary technique.
