Charred Spring Onion Dip

Use thick yogurt in place of the sour cream, for a  healthier dip with a little extra tang.

1 bunch of spring onions, thinly sliced, greens included 2 tablespoons olive oil
Kosher salt
1 garlic clove, grated
1⁄2 cup mayonnaise
1⁄2 cup sour cream/thick yogurt
2 teaspoons fresh lemon juice
1 teaspoon chopped fresh thyme, plus more for serving
2 TBSP buttermilk (buttermilk shortcut: 1 cup milk + 2 TBSP lemon juice/vinegar, let sit for 15 min)
Freshly ground black pepper
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Heat broiler, toss sliced spring onions with olive oil and salt and pepper. Place on lined baking sheet and broil, stirring once, until charred, about 10-15 minutes. While waiting, combine all other ingredients. Let onions cool, then add to the mixture.