Grilled Beef Tenderloin with Roasted Garlic Sauce and Leek-Tomato Quinoa

Preheat oven to 350 °F. Combine milk and garlic in small saucepan. Simmer, uncovered, over medium heat 10 minutes. Drain; discard milk. Place garlic heads, cut side up, in small ovenproof dish. Pour 1/2 cup oil over. Cover dish tightly with foil. Bake until garlic is soft, about 55 minutes. Remove garlic from oil; cool. Pour oil from dish into measuring cup; add more oil if necessary to measure 1/2 cup total. Squeeze out garlic from peel into blender. Add 1/2 cup broth and garlic oil; puree until smooth, thinning with more broth if desired. Season with salt and pepper. (Can be made 1 day ahead. Cover; chill. Rewarm over medium-low heat and thin with more broth, if desired, before serving.)