Rinse fresh blue mussels in tap water, scrubbing and removing beard.
Heat olive oil in a large pot. Sauté vegetables a few minutes. Add wine, bring to boil. Add fresh blue mussels, cover and cook over high heat until shells open, 5 to 7 minutes. Remove mussels from shells, keeping some in the shell for garnish.
Cook pasta according to instructions. Drain. Rinse with cold water and drain again.
Heat olive oil in a large frying pan. Add mushrooms, red peppers, garlic, shallots, and cook for 3 minutes.
Add mussels, parsley, cooked spaghetti, and heat well. Season to taste with salt and pepper.
Serve immediately on warm plates and garnish with mussels in shell.