Cook rotini pasta while you are cooking the chicken. This will make all of it come together at the same time so that everything will be nice and hot.
In large frying pan, melt 2 tbsp butter and add chicken that has been cut into bite size pieces. Add garlic and cook until chicken is completely cooked.
Cut cheese into 1" squares and add to chicken when it is completely cooked. As it starts to melt, add milk. If it is not as creamy as you would like it once it has all melted, you can add more milk. Be sure to stir often so as not to burn the cheese.
When pasta is finished cooking, drain and immediately pour chicken and cheese mixture on top and mix thoroughly. Pour into buttered casserole dish, top with croutons and melted butter. Cook in 400 degree oven until golden brown ~ about 5-7 minutes. ENJOY!!
If you do not want to do this as a casserole, omit the croutons and butter and just mix and enjoy!!