Sole With Beet Sauce with greens

6 tablespoons olive oil 1 3/4 cups sliced leeks (white and pale green parts only, from 2 medium) 2 large garlic cloves , chopped 1 teaspoon dried thyme 1 bay[...]

cooking spray 1 lb fillet of sole (or other thin fish fillets) 2 tablespoons fresh parsley , minced 1 tablespoon fresh mint , chopped 2 teaspoons vegetable[...]