How Much Leek to Substitute for Onion
Works for baking, sauteing, and slow cook. Leek comes across milder than Onion.
How much leek equals one small onion?
Use 1 1/2 stalks leek (white and light green parts) per small onion.
Health notes
Compared with Onion, Leek has: more calories (61 vs 40 per 100g in Onion) and more carbs (14.2g vs 9.3g per 100g in Onion).
Using leek as an onion substitute in baking
Use 1 1/2 stalks leek (white and light green parts) per small onion. Gratins and casseroles turn out milder and softer, less sharp bite.
Other cooking methods
- Sauteing
1 1/2:1; cook a bit longer since leeks release more water. Good base for soups and pan sauces.
- Slow Cook
1 1/2:1; leeks melt down soft and sweet in braises and stews, close to a slow-cooked onion.
- Grilling
1 1/2:1; halve stalks lengthwise and char. Softer texture than grilled onion wedges, milder taste.
- Steaming
1 1/2:1; slice and steam until tender, works well in fillings and gratins.
- Raw Cold
1 1/2:1, thinly sliced; much milder than raw onion, good in salads where you want crunch without the bite.
Methods to avoid (2)
- Frying
Not recommended: leeks turn limp and stringy instead of crisping up like onion rings or fried onion bits.
- Drinks
Not recommended: leek adds no useful flavor to drinks and won't dissolve or infuse well.
FAQ
- How much leek equals one small onion?
1 1/2. For a typical recipe:
- 1 small onion → 1 1/2
- 2 small onions → 2 1/2
- 3 small onions → 3 1/2
- Can I substitute leek for Onion in baking?
Yes. Use 1 1/2 stalks leek (white and light green parts) per small onion. Gratins and casseroles turn out milder and softer, less sharp bite. Not recommended: leeks turn limp and stringy instead of crisping up like onion rings or fried onion bits.
- How much leek to use as an onion substitute?
Milder and sweeter than onion; add a little garlic or a pinch of extra salt to bring back punch.
- How does the flavor change when substituting Leek for Onion?
Leek comes across milder than onion.
- How does texture change when substituting Leek for Onion?
Leek softer and more slippery once cooked, with less crunch raw and a looser bite even after browning.
- What else should I know about substituting Leek for Onion?
For soups, braises, gratins, and slow-cooked stews. Expect a softer bite and a gentler, sweeter background flavor instead of a sharp onion punch. Skip fried onion rings or crispy fried toppings, since leek turns stringy and limp rather than crisp. Also skip drinks and cocktails, leek won't infuse. Add garlic or a splash of onion powder if the dish needs more bite.
- What still works when substituting Leek for Onion?
Leek still works as a flavor carrier, texture, and moisture.
- What won't work when substituting Leek for Onion?
Leek won't work as a sweetener.
- How well does Leek match Onion?
Leek is good on structure, okay on heat, and okay on flavor.
- How does nutrition compare per 100g when substituting Leek for Onion?
Leek is higher in protein, and has about x2 more calories and x3 more fat. Overall, sat. fat is similar.
- How do the flavor notes shift when substituting Leek for Onion?
The flavor shifts toward less acidic, less pungent, and less umami notes.