Chop pancetta into small cubes. Slice zucchini into short sticks. Quarter mushrooms.

Grate cheese. Mix 100g cheese with milk. Set aside remaining cheese for topping.

Preheat oven to 70C (warm).

Start boiling large pot of salted water.

Put pancetta in large skillet/dutch oven and bring up to heat slowly on medium-low heat. Cook until fat has liquified and meat is crispy, about 10 minute.

Strain pancetta into small container, keeping all oil in the skillet. Keep pancetta in warm oven.

Add olive oil, zucchini, and mushrooms to skillet. Cook until most liquid has come out and boiled off, about 10 minutes. Remove from heat.

Transfer vegetables to a bowl, retaining all liquid in skillet. Put in warm oven.

Add bucatini to boiling water and add butter to skillet. Boil bucatini 5 minutes.

Mix saffron with about 50ml of pasta water in small container.

Put skillet back on high heat and transfer bucatini to skillet with pasta spoon.

Add saffron water to skillet and stir.

Boil off water while stirring constantly. Add 1 ladle of pasta water each time skillet gets dry. Continue until bucatini is cooked al dente, about 5 minutes.

Add vegetables and half a ladle of pasta water, stir until dry.

Add cheese/milk combo and stir very well to combine. Remove from heat.

Plate, top with pancetta, cheese, and freshly ground pepper.