Say goodbye to winter with a burst of spring green on your burger: a pile of charred spring onion tops and a drizzle of garlicky and minty chimichurri.
Allergen Note: Contains milk, eggs, wheat, soy.
To make the chimichurri, trim and finely chop 1 spring onion, including the bulb and green. Finely chop 2 cloves of garlic. Pick a small handful of mint leaves, toss the stems, and thinly slice the leaves (you should have about 1 tablespoon). In a small bowl, stir together the finely chopped spring onion, garlic, mint, 2 tablespoons red wine vinegar, 2 tablespoons olive oil, ½ teaspoon salt, and a few grinds of pepper.
Trim the remaining greens from the spring onions, tossing the bulbs, and cut the greens half crosswise. Season the patties on both sides with salt and pepper.
In a large cast-iron skillet or frying pan over medium-high heat, warm 1 tablespoon olive oil. When the pan is smoking hot, add the patties and sear until browned and done to your liking, 3 to 5 minutes per side for medium. Transfer the patties to a plate.
Wipe out the pan, return it to the heat, and warm 1 tablespoon olive oil. Add the greens, season with salt, and cook until soft, brown, and charred in spots, 2 to 3 minutes. You can press down with a spatula to help them char, and stir once or twice. Transfer to a cutting board, let cool briefly, and roughly chop.
Wipe out the pan, and return it to the heat. Split the burger buns in half. Working in batches if necessary, place them cut-side down in the pan, and toast until warmed, 1 minute.
To assemble the burgers, place the buns on plates, and spread with the aioli. Stack with the patties, pile with the charred green onions, drizzle with the chimichurri, and serve warm.