Ham and Split Pea Soup Recipe

Name: Ham and Split Pea Soup Recipe
Ingredients: 1 tablespoon butter; 6 ounces ham steak (or thickly cut ham), cut into 1/2 inch pieces; 1 medium leek, white and light green parts only, finely chopped (about 1/2 cup); 1 small onion, finely chopped (about 3/4 cup); 1 medium carrot, peeled and finely chopped (about 3/4 cup); 1 celery stalk, finely chopped (about 1/2 cup); 2 bay leaves; 6 sprigs thyme; 2 small smoked ham hocks (about 3/4 pound total); 1 pound green split peas, rinsed and picked over; 2 quarts (8 cups) water or low-sodium store-bought or homemade chicken broth; Pinch of red pepper flakes; Kosher salt and freshly ground black pepper; Lemon juice, to taste; Sour cream or plain yogurt for serving