Tuna Tetrazzini

2 (7 oz) cans tuna
6 T chopped onion
2 T salad oil
2 (10 1/2 oz) cans cream of mushroom soup
1 1/3 c water
1/2 c grated Parmesan cheese
1 small can pitted black olives sliced
2 T chopped parsley
2 t lemon juice
Pinch thyme
Pinch marjoram
1/2 lb spaghetti

Saute the onion in salad oil until golden brown. Add mushroom soup, water and 1/4 cup Parmesan cheese. Drain and flake the tuna into bite size pieces. Add tuna and olives to sauce. Mix together and heat thoroughly without breaking the tuna pieces. Season the sauce the parsley, lemon juice, thyme and marjoram. Cook the spaghetti according to directions on package. Mix the cooked spaghetti with sauce and pour into greased 3 quart casserole. Top with remaining grated Parmesan cheese. Heat under broiler until hot and bubbly. Six to eight servings.