Step 1

Add about 4 inches of water to a large pot and bring to a boil over high heat.

Step 2

Cook pasta according to the manufacturer's instructions. This typically entails boiling for about 8-12 minutes, or until barely al dente.

Step 3

Remove the pasta from the water and set aside.You may want to stir it occasionally to keep the noodles from sticking together.

Step 4

Grate gruyère and Swiss cheese into a small bowl and toss with cornstarch. Make sure that all of the pieces are lightly coated.This will help the cheese from separating when you cook it. If you're having a tedious time getting the cornstarch coated without clumping, add the mixture to a large Ziplock bag and shake.

Step 5

Meanwhile, heat a medium saucepan over medium heat.

Step 6

Add wine and lemon juice to the saucepan and bring to a simmer.

Step 7

Once the wine mixture begins to simmer, slowly stir in the cheese about 1/4 cup at a time. Make sure to stir constantly until fully incorporated.The key to a creamy fondue is adding in the cheese gradually. If it’s added too quickly, the mixture will separate!

Step 8

Once all of the cheese is incorporated and the mixture is smooth, stir in the Kirsch and mustard.

Step 9

Add rigatoni to the sauce and stir until combined.