Easy Stovetop Gluten Free Mac and Cheese

to 20 ounces small dried gluten free pasta (I used Barilla gluten free pasta elbows)

to 2 tablespoons (14 to 28 g) extra-virgin olive oil

unsalted butter, chopped

gum-free gluten free flour blend (31 grams superfine white rice flour + 10 grams potato starch + 6 grams tapioca starch/flour)

low-fat evaporated milk

to 2 1/2 cups (16 to 20 fluid ounces) milk, at room temperature (any kind, just not nonfat)

semi-hard cheese, shredded (a mix of mozzarella and cheddar cheeses is nice, or all cheddar)

kosher salt, or to taste

freshly ground black pepper, or to taste