Wipe mushrooms clean with a damp paper towel. Pop stems off caps. Slice caps into 1/4 inch thick slices. Slice stems.

Heat up a pan and add vegetable oil. Add mushroom caps and stems. Sauté until soft. Add minced garlic, chopped thyme if using and sauté until garlic is soft. Careful not to brown garlic. Add more oil to pan if necessary and lower heat if you need to.

When garlic is soft, add 1/4 tsp coarse salt and 1/4 tsp ground black pepper. Stir and heat for one minute. Remove mushrooms from pan and set aside.

To the empty pan, add butter and melt. Add flour and stir, cook for a minute. Stir in milk and bring to a boil. Cook for 30 seconds. Add mushrooms and stir. Taste and adjust salt and pepper. Sauce can be mixed with cooked pasta and served. If you wish, add grated parmesan to sauce before mixing with pasta. Garnish with chopped parsley if desired.

Boil water, add 1 tbsp coarse salt and cook pasta until tender. Cook pasta and sauce at the same time, so they will be ready to eat. Cooked pasta can be taken out of water and added directly to pan with sauce. Use a little pasta water to thin out sauce if you need to. Toss pasta well with the sauce and serve hot.