1 1/2 tablespoons extra-virgin olive oil, divided
1 cup chopped onion
1 teaspoon chopped fresh thyme
5 garlic cloves, chopped
1 pound cubed peeled baking potato (about 2)
1 pound cubed Yukon gold potato (about 4)
5 cups unsalted chicken stock (such as Swanson)
1 teaspoon kosher salt, divided
1 bay leaf
1 pound cauliflower, cut into florets (about 1/2 head)
3/4 teaspoon freshly ground black pepper, divided
Cooking spray
1 1/2 cups 2% reduced-fat milk
3/4 cup chopped green onions, divided
1/2 cup fat-free fromage blanc (such as Vermont Creamery) or sour cream
2 ounces grated sharp cheddar cheese (about 1/2 cup)
4 slices center-cut bacon, cooked and crumbled