Fresh mint will have a lighter flavor than dried mint. If you use dry mint over fresh mint, use a smaller quantity for the same or similar taste. So, if a recipe asks for one teaspoon of fresh mint, opt for half a teaspoon of dry mint. You can add more if you think you need more, but do taste tests each time you add more mint to avoid too much minty-ness. You can also use fresh mint instead of dried mint, doubling the amount needed and tasting your food until it reaches your desired flavor.