Overall, environmental science is the field of science that studies the interactions of the physical, chemical, and biological components of the environment and also the relationships and effects of these components with the organisms in the environment.
1 Add onions to glass jars or a bowl. 2  Toast cinnamon, cloves and the red pepper flakes in a small saucepan over medium heat until fragrant, 3 to 5 minutes. 3  Whisk in vinegar, lime juice, a 1/4 cup of the sugar and salt. 4  Bring to a simmer and cook until sugar and salt have dissolved, 1 to 2 minutes.
Prep the Onions. The best onions to use for caramelizing are sweet onions, since they tend to be juicy with a mild, sweet taste. Some popular sweet varieties include Maui, Vidalia, and Walla Walla onions. For four to six 1/3-cup servings, start with two large onions and peel away and discard the outer papery layers. Slice the onions into thin slices or cut into 3/4-inch chunks. Melt the Butter. Butter offers the richest flavor, but you can caramelize onions in other fat such as margarine or olive oil.