Prepare spaghetti in a pot of salted boiling water, 6-7 min. It should be al dente and not fully cooked. Drain the water and set aside pasta.
Heat olive oil and butter on low heat in a sauté pan.
Add garlic, crushed red peppers, sauté for 1 minute to release the aroma. Add chopped stems of fresh Italian Parsley, sauté for 1 min.
Add mushrooms, sauté for 2 min.
Add tomatoes with their juice, sauté for 2 min. Add a pinch of salt, thoroughly mix ingredients.
Add wine to deglaze pan, scrape the pan to make sure you get all the flavor off. Add optional Dasida bouillon and water.
Turn heat to med. When it gets hot enough, add shrimp and optional sausage, stir for 2 minutes.
Add spaghetti pasta. Add remainder of fresh Italian Parsley. Add 1/4 cup of parmesan, stir. Squeeze in lemon before serving.
Serve into 3 plates. Layer pasta, then clams, then sauce, then parmesan on top. Cut wedges of out of remaining lemon, serve to taste.