Cut the tops of the garlic bulbs and place then in a baking pan that snugly fits them. Tuck in the rosemary sprigs and whole dried chilies. Drizzle half the lemon juice and a teaspoon of olive oil. Tuck in one half of squeezed lemon into the pan. Bake at 350F for 30 minutes until the garlic cloves are really soft to touch.
Squeeze out the cloves. In a food processor, pulse the roasted garlic the remaining ingredients and one crushed chili pepper into a smooth paste.