Yield: 4 portions
Preheat oven to 350° F. Cook pasta according to package directions.
While pasta cooks, heat olive oil in a large non-stick skillet over medium-high heat. Add a single layer of mushrooms and cook, without stirring, for about 5 minutes or until mushrooms become red-brown on one side. Flip mushrooms and cook about 5 minutes more, until other side is same color.
Melt butter in a large saucepan and stir in flour. Cook for a minute or two to slightly toast flour. Stir in salt and whisk in milk. Bring to a low boil over medium-high heat, stirring occasionally to slightly thicken sauce, for about five minutes. Remove sauce from heat, whisk in cheeses, rosemary and thyme and stir to melt. Stir in mushrooms and pasta and divide between four one-cup ramekins.
Place ramekins on baking sheet and bake until cheese bubbles around edges, about 15 to 20 minutes. Remove from oven and let rest for about five minutes. Serve warm.