To something is to slowly mix in a bit of with eggs or cream to raise the temperature slowly. This prevents the cream from curdling (turning lumpy and gross) or the eggs from scrambling in your sauce.

temper; hot sauce

Explanation:

The context clue here is "raise the temperature slowly" gives a quick clue to temper (as a verb). The 4th definition of temper (as a verb) is "to bring to a suitable state by mixing or adding a usually liquid ingredient." Knowning, this leads to the second blank being hot sauce, as that's a liquid.

iron would move it is magnetic there is a mag field around the current in the wire