In a Dutch oven combine potatoes, water to cover, and about half of the salt. Bring to boiling. Reduce heat and simmer, covered, until potatoes are tender, reserving 1/2 cup cooking water. Drain potatoes and return to pot.
In a skillet heat olive oil with garlic and cook for 1 minute until garlic starts to brown. Mash into potatoes along with cooking water, crumbled blue cheese the rest of the salt, and crushed red pepper to taste.