Vegetarian linguine with cherry tomatoes and black garlic

A few hours before making the dish:
Cut the black garlic in half and remove the cloves, reserving them with a little oil.
In a bowl, place the onion cut into strips (half-moon) and leave them dipped in oil with the skin of the black garlic (to catch the taste of the garlic) for about 3 hours or more.
Chop the parsley well and cut the tomatoes in half.
Cook the dough according to the package orientation. Reserve some of the water used for cooking.
Remove the garlic peel from the bowl with the onion, and pour this oil into a frying pan and brown the grated garlic (common). Add the tomatoes, black pepper to taste and a teaspoon of salt.
Add the cooked pasta and 100 ml of cooking water. Mix gently.
Add the chopped parsley and season with 3 tablespoons of soy sauce.
Mix and taste the salt. If still missing, add more soy sauce, being careful not to salt.
Turn off the heat, as the dough is ready.
Serve the dough with the pieces of black garlic and the pout pepper on top and, optionally, with grated parmesan.