Preheat the oven to 300 degrees . Line a baking sheet with foil, coat with cooking spray, and add the garlic slices in an even layer. Spray again with the cooking spray. Bake until golden and crisp, about 15 minutes.
Meanwhile, in a large pot, heat the EVOO over medium heat. Add the chopped garlic and onion and cook until softened, about 5 minutes. Add the chickpea flour and cook, stirring, for 1 minute. Stir in 1 cup water, the clams and their liquid, the potatoes, milk and thyme sprigs. Bring to a boil, stirring, then lower the heat and simmer, stirring often, until the potatoes are tender and the soup is thickened, 15 to 20 minutes. Season with salt and pepper. Top with the baked garlic chips, paprika and thyme leaves.