Heat the oil in a soup pot over medium-high heat. Melt 3 tablespoons butter into the oil; when it foams, stir in the potatoes, bell pepper, celery, carrots, onion, chili pepper, garlic, salt, black pepper and thyme. Partially cover the pot and cook, stirring occasionally, for 7 minutes to soften the ingredients. Add the corn and heat through. Stir in the flour and cook for 1 minute; add the beer and stir for 1 more minute before adding the stock and the Sriracha (or hot sauce). Bring to a boil, then reduce to a simmer. Adjust the seasonings, to taste. If the chowder gets too thick, thin it with some water.
In a small bowl, stir together the softened butter with the blue cheese crumbles. Turn on the broiler; toast the English muffins on both sides, then slather with the blue cheese butter.
Ladle the chowder into shallow bowls, top with scallions and serve with blue cheese-buttered English muffins alongside.