Kraft Tuna Mac

Found this on a message board ages ago...no idea who's it is

• Ready In: 40 mins
• Serves: 4

Ingredients

• 1  box  of kraft original macaroni and cheese
• 1⁄2 cup  frozen peas
• 1  can  campbell's  cream of celery soup or 1  can  cream of chicken soup
• 1⁄2  soup can  whole milk
• 1  tablespoon mayonnaise
• 1⁄4 cup butter, sliced
• 1 (12 ounce) can solid white tuna
• 1⁄2 cup  crushed garlic bagel chips
• 1⁄2 cup parmesan cheese, divided

Directions

1. Preheat oven to 400 degrees.
2. Cook pasta in salted water to very al dente. In the last few minutes of pasta cooking time toss the frozen peas into the boiling water. Drain.
3. Meanwhile in a medium sized oven proof bowl, add soup, milk, mayonnaise and the contents of cheese flavor package and stir until smooth. Add half of the parmesan cheese and the tuna and mix, breaking up any large chunks of tuna. Add pasta to bowl and without stirring add butter slices and allow hot pasta to melt the butter. When butter has melted, mix well. Top the casserole with the remaining parmesan cheese and then the crushed bagel chips.
4. Bake casserole until browned and bubbling 25 to 30 minutes.