3 tablespoons (45g) unsalted butter
1 medium onion, finely diced (about 6 ounces; 170g)
1 large rib celery, finely diced (about 4 ounces; 125g)
6 ounces (170g) ham steak, diced (see note above)
2 medium cloves garlic, minced
1 pound (450g) dried green split peas
6 cups (1.5L) homemade or store-bought low-sodium chicken stock, or water
2 bay leaves
Kosher salt and freshly ground black pepper
Melt butter in a pressure cooker over medium heat. Add onion, celery, and ham and cook, stirring, until softened but not browned, about 3 minutes. Add garlic and cook until aromatic, about 30 seconds.
Add peas, chicken stock or water, and bay leaves. Stir to combine, then cover pot and bring to high pressure. Cook for 20 minutes, then rapidly release pressure by opening the air valve. Open pot lid, stir contents until smooth, season to taste with salt and pepper, and serve. Carefully clean the pressure cooker’s gasket and valves as soon as the pot is cool enough to handle; pea soup can easily clog valves, which can cause your cooker to over-pressurize the next time you use it. Soup can be stored in the refrigerator for up to 1 week.