Duelist

When you are wielding a finesse weapon you are proficient with and another creature hits you with a melee attack, you can use your reaction to add your proficiency bonus to your AC for that attack, potentially causing it to miss you. If the attack misses, you can make one melee weapon attack against the attacker as part of this reaction.

You can make this attack a number of times equal to your proficiency bonus, and regain all expended uses when you finish a long rest.