6 slices day-old Italian bread, cut into 1/2-inch cubes
1/4 cup olive oil
4 tablespoons butter
4 cloves garlic, crushed
1 1/4 cups red lentils, rinsed
4 carrots, chopped (about 2 cups)
2 stalks celery, chopped (about 1 cup)
1/2 onion, chopped (about 1 cup)
4 cups vegetable stock (one 32-ounce carton)
3 sprigs fresh thyme
1 dried bay leaf
Kosher salt and freshly cracked black pepper
1 cup jarred marinara sauce
1 cup mild salsa
1 cup frozen peas
1/4 cup fresh flat-leaf parsley, chopped, plus more leaves for garnish
1/4 cup sour cream
2 tablespoons extra-virgin olive oil