Store-bought spaghetti sauce is convenient because it saves an hour or more of simmering the sauce until the flavors blend. However, the flavor of many store-bought sauces can be disappointing. Some sauces contain little more than the tomato and water, which makes for uninteresting and bland spaghetti. Add spice to the sauce to rev up the flavor and give the sauce a spicy kick with red pepper flakes and diced green chilies. In Italy, this spicy sauce is called "arrabiata" sauce, which means "angry," because of its hot flavor.
Pour 2 tbsp. olive oil into a saucepan and heat it over high heat until it begins to sizzle in the pan.
Add 1 tsp. red pepper flakes and stir them into the oil with a slotted spoon. The pepper flakes will make the oil hot which, in turn, will flavor the sauce.
Add the 2 diced jalapenos with the seeds, if you opt to use them. Traditional arrabiata uses either hot chilies or red pepper flakes, depending on the recipe, but use both if you prefer a very hot arrabiata with a complex flavor.
Reduce the heat to low and add the 16 oz. spaghetti sauce. Simmer the sauce uncovered for 15 minutes to 1 hour. The longer you simmer the sauce, the spicier and more flavorful it will become.
Serve the sauce over spaghetti or other pasta.