Arrange a rack in oven to the center and preheat oven to 350 degrees
Remove husks from corn and then cut off the corn kernels from the cob.
Pour the corn kernels on a baking sheet in a single layer and roast corn for approximately 35-40 minutes until a mix of golden and brown kernels result. Don't worry if they are crispy; this is good!
While the corn is roasting, melt ¼ pound of butter in a large pot over medium-low heat.
Add red bell pepper, onion, and garlic and saute for at least 10 minutes until onion is translucent and red bell pepper is soft.
Whisk in flour until it is evenly distributed and incorporated into the pepper/onion/garlic mixture.
Slowly add milk and cream, whisking vigorously to combine.
Reduce heat to low and simmer until sauce is thickened (about 10 - 15 minutes).
Add grated cheeses slowly.
Season with salt and pepper.
Remove from heat and let cool slightly.
Remove corn from oven when finished roasting to a mix of nice golden and brown colors, but do not turn off the oven.
Let corn cool slightly, then add the corn to approximately 4 cups pepper jack sauce in a large bowl and stir gently to incorporate (add more to taste if necessary, and freeze remaining pepper jack sauce for later use).
Pour corn mixture into a greased ovenproof casserole dish.
In a small skillet, melt 2 tablespoons butter over medium-low heat and add panko breadcrumbs, stirring continuously until breadcrumbs are golden brown and toasted.
Sprinkle breadcrumbs on top of corn mixture and place in the oven an additional 10-15 minutes.
Garnish with diced chives, if desired.
Serve immediately.