For the stuffed peppers: Bring a large pot of water to a boil. Add the macaroni and cook until al dente according to the package directions; drain.
Heat the milk and butter in a large saucepan over medium heat. Add the cheeses and cook, stirring, until melted. Stir in the kosher salt, seasoning salt and pepper. Add the macaroni and stir into the cheese sauce.
Make a slit in each pepper and remove the seeds. Gently stuff a heaping 1/4 to 1/2 cup of the macaroni into each pepper, being careful not to overstuff. Use a toothpick to help seal the peppers and set aside.
For the cilantro-lime cream: In a small bowl, whisk together the sour cream, cilantro, cumin, salt and lime zest and juice until well combined. Set aside.
For the batter: In a large heavy-bottomed pot, add enough oil to fill the pot halfway and heat the oil to 375 degrees F.
Whisk together the flour, baking powder, salt and pepper. In a large measuring cup, mix together the beer and eggs. Whisk the liquid into the dry ingredients until well mixed.
When the oil is ready, dip a pepper into the batter until fully coated. Carefully, slowly lower the pepper into the hot oil. Repeat with the remaining peppers. Fry until golden brown and crisp, about 2 minutes. Drain on a paper towel-lined plate. Serve immediately, drizzled with the cilantro-lime cream.
To roast and peel the poblanos, broil the peppers until charred, then transfer them to a resealable plastic bag, seal the bag and let them sit for about 20 minutes. Remove them from the bag and peel off the skins.