Prepare the Mushrooms: Rinse the 10 SMALL WHITE MUSHROOMS twice - Drain them in a basket and then dry with paper towels - Slice the MUSHROOMS thinly with a knife

Prepare the SAUCE, ONION, and GARLIC: Rinse the 4 CAPERS - Blend 3/4 cup of CANNED PEELED TOMATOES with the 4 CAPERS until you get a PUREE - Peel 1/4 of a YELLOW ONION and chop finely - Peel and remove the germ from a CLOVE OF GARLIC, then chop finely with a knife

Prepare the Tuna and Cheese: Drain a can of 2.8 oz TUNA IN OLIVE OIL in a strainer over a glass - Once the OIL has drained, place the TUNA in a bowl and shred with a fork - Grate 1 teaspoon of Parmesan

Cook the Sauce: Put the OIL from the CAN OF TUNA in a pan over medium heat until it reaches 250°F - Reduce to low to medium heat, add the CHOPPED ONION, CHOPPED GARLIC, and 1/2 teaspoon of CHILI POWDER - Stir and let brown for 7 minutes - Add the TOMATO and CAPER PUREE, the SLICED MUSHROOMS, and let cook for 10 minutes over low to medium heat, stirring occasionally

Cook the Pasta (while the Sauce is Cooking): Boil a large pot of WATER and SALT it - Once boiling, add 2.8 oz of SPAGHETTI, submerge in the WATER, and cook partially covered for 12 minutes -

Add the Pasta and Tuna: Using tongs, place the COOKED SPAGHETTI in the pan - Add the SHREDDED TUNA - Mix everything with a spatula and add 1 or 2 ladles of PASTA COOKING WATER to thin the SAUCE if necessary - Add SALT lightly if needed

Plating: Using fine tongs, arrange the SPAGHETTI in a roll on a plate - Scrape the remaining SAUCE from the pan with a spatula and place it on the SPAGHETTI - Cover with GRATED PARMESAN