Little Balsamic-Glazed Onions

Ingredients

• 0.3 cup balsamic vinegar 
• 0.5 teaspoon pepper black freshly ground
• 3 tablespoons butter 
• 2.5 pounds cipollini onions 
• 1 tablespoon thyme leaves fresh
• 1 bunch green onions cut into 2-in. lengths
• 0.5 teaspoon kosher salt 
• 3 tablespoons olive oil extra-virgin divided
• 2.5 pounds pearl onions red
• 1 cup vegetable broth reduced-sodium

Equipment

• bowl
• frying pan
• pot
• slotted spoon
• colander
• cutting board
• serrated knife

Directions

1. Add half of cipollini to a pot of boiling water; simmer 1 minute, then transfer to a colander with a slotted spoon and immediately rinse with cold water. Repeat with remaining cipollini, then pearl onions (in 2 batches), then garlic.
2. With a small, sharp serrated knife, trim root ends and peel onions and garlic on a cutting board, slitting each lengthwise and holding your thumb against the pointy tip to keep its core from squirting out; then trim any fibrous tips. Put onions and garlic in a bowl and drizzle with 1 tbsp. oil, the thyme leaves, pepper, and salt.
3. Mix to coat.
4. In a large frying pan, heat remaining 2 tbsp. oil over medium-high heat.
5. Add onions and garlic, and saut, stirring often, until most are partly browned.
6. Add vinegar and broth; reduce heat to medium-low and simmer until onions are tender and some are falling apart, 10 to 20 minutes. Stir in green onions and butter.
7. Using a slotted spoon, transfer onions to a serving bowl; cover. Boil sauce over high heat until syrupy and reduced to about 3/4 cup, about 4 minutes. Stir gently into onion mixture; top with thyme sprigs.
8. Make ahead: Chill airtight up to 2 days (add green onions and thyme sprigs only at end).