Prep: 30 minutes
Total: 3 hours 30 minutes
for the roasted garlic butter:
3 heads garlic (about 5 ounces)
1 tablespoon neutral vegetable oil
1 cup unsalted butter, at room temperature
for the soup:
2 cups dried Sea Island red peas, rinsed
a small sachet (4 medium thyme sprigs, 1/2 fresh bay leaf, 1 garlic clove, 1 teaspoon black peppercorns wrapped in cheese cloth)
1/4 cup neutral cooking oil
1 yellow onion, minced
2 pounds collard greens, stemmed and chopped (reserve stems for pickling)
1 teaspoon dried chile flakes, toasted
1/2 cup dry white wine
1/4 cup cider vinegar
2 tablespoons roasted garlic butter
freshly ground black pepper
1. Make the garlic butter: Heat a convection oven to 375°F or a regular oven to 400°F. Slice off the tip and tail of each head of garlic to expose the cloves and place, root ends down, in a small baking dish. Drizzle with the oil and cover tightly with foil. Transfer to the oven and roast for 1 hour and 15 minutes. Let cool slightly.
2. When the garlic is cool enough to handle, squeeze the cloves from their skins. Place the garlic in a food processor and purée until smooth. Using a plastic spatula, push the garlic through a fine-mesh sieve set over a bowl.
3. In the bowl of a stand mixer fitted with a paddle attachment, add the butter and the garlic purée and beat on medium speed until completely combined, about 5 minutes. Scoop into the lidded containers and store in the refrigerator, up to 2 weeks, or freeze for up to 3 months.
4. Make the soup: Place the peas in a large bowl, cover with cold water, and let soak for 3 hours. Drain the peas and transfer to a large stockpot. Add 2 quarts cold water and the sachet and bring to a boil over high heat. Reduce to a simmer and cook until the peas are tender but still holding their shape, about 30 minutes. Remove from the heat and stir in 1 tablespoon salt. Let the peas cool in their liquid to room temperature.
5. In a large stockpot over medium heat, warm the oil. Add the onion and cook until softened, 5 to 7 minutes. Add the greens and stir to coat with the onions and the oil. Season lightly with sea salt and chile flakes. Stir for 2 minutes to let the seasoning permeate the ingredients. Add the wine and cook, stirring every few minutes, until the greens are very tender and breaking down slightly, 30 to 40 minutes. Meanwhile, drain the peas, reserving 1 cup of the cooking liquid.
6. Once the greens are tender, stir in the cooked peas and vinegar. Bring to a simmer and add the garlic butter. Season with salt to taste and a few cranks of the pepper mill. If the mixture is looking dry, add the reserved pea liquid by the tablespoon. Simmer for 10 more minutes, allowing all of the ingredients to come together.