Multi-Color Cauliflower with Béchamel (Bill Yosses)

Multi-Color Cauliflower

• 10 oz red onions, quartered
• 2 oz extra virgin olive oil, divided
• 2 heads cauliflower, mixed (purple, Romanesco, orange, white), stalks, stems, leaves removed
• ½ tsp salt, to taste
• ½ tsp ground black pepper, to taste
• 30 oz water

Béchamel Sauce

• 6 oz Gruyère cheese, aged, in pieces
• 1 oz unsalted butter
• 1 oz extra virgin olive oil
• 2 oz all-purpose flour
• 24 oz whole milk
• 1 tsp salt
• 1 tsp white pepper
• fresh thyme, to garnish