Cut the garlic bulbs across the top to expose the very top of the cloves.
Set the bulbs on a piece of aluminum foil then drizzle with oil and sprinkle with salt and pepper.
Close the foil around the garlic tightly and roast for about 45 minutes or until very tender (when done, you should be able to squeeze the garlic out of the head easily; the cloves will be darkened but not burned).
Allow to cool, then remove the roasted garlic by gently squeezing it out the top of the head. Set aside.
Prepare the Pasta and Sauce
Cook the penne pasta according to package directions.
Meanwhile, heat a small amount of oil in a skillet and add the shallots.
Sauté shallots until light brown, add chicken broth and garlic.
In a small container, mix the water and cornstarch well.
Bring skillet ingredients to a boil and add milk and cornstarch that has been diluted in the water.
Place mixture into a blender (or place into a bowl and use an immersion blender) and blend until smooth.
Place shrimp in skillet and sauté until done.
Add the creamy garlic mixture back to the skillet and season with salt, pepper, and cilantro.
Add the cheese and allow to thicken.
Serve over prepared penne pasta.
Roasted garlic freezes well, and it’s just as easy to roast a whole panful as it is to roast two bulbs. To freeze, squeeze the cloves out of the bulbs gently and place in a single layer on a pan that will fit in the freezer. Place in freezer until frozen through, then remove from freezer and place together in a freezer container labeled with the date and “Roasted Garlic Cloves.”