code

 const A = Pizzas.reduce((acc, {w}) => ( new Set([...acc,...w]) ),new Set);

const AA = new Set(Pizzas.reduce((acc, {w}) => ([...acc,...w]),[]));

const C = Pizzas.reduce((a, {w}) => {

  for (let ing of w){

   if (!a[ing]) a[ing] = 0;

   a[ing]+=1;

  }

  return a;

  },{});

for (let [ing, nb] of Object.entries(C)){

  console.log(`${ing} : ${nb}`);

}

/*************************************

const sum = (accumulator, currentValue) => accumulator + currentValue,

      max = (accumulator, currentValue) => Math.max(accumulator,currentValue),

      sortDist = (a, b) => (a.price > b.price ? -1 : 1);

function add( pizza ){

  let t = [];

  for (let inc of pizza.w){

      t.push(price.get(inc))

  }

  pizza.price = t.reduce(sum);

  return pizza

}

let g = Pizzas.map( add );

console.log(g)