Kabocha Salad

Bahan-bahan (4 porsi)

• ½ kabocha squash ((2.4 lbs, 1 kg with seeds))
• ½ red onion ((5 oz, 160 g))
• 5 slices ham ((3 oz, 90 g; optional))
• 2 Tbsp Japanese Kewpie mayonnaise
• 2 Tbsp cream cheese ((I use cream cheese spread that comes in a tub that's easy to mix))
• ¼ tsp Diamond Crystal kosher salt ((plus a pinch for salting the onion))
• ⅛ tsp freshly ground black pepper