Cut cauliflower into 1 1/2 inch slices as shown below. Some chunks my fall away from slices , you can use them for someting else or just grill them with the slices

Bring a large pot of saled water, or chicken broth to a boil, blanch cauliflower slices for 2 minutes.

Remove and pat dry

Combine olive oil, rice vinegar,tamari soy sauce, pepper and the 1/2 teaspoon sriracha salt in a small bowl, brush cauliflower all over with mixture

Whisk in the top of a double boiler the egg yolks, lemon juice, cream, sriracha salt, pepper and hot sauce

Place pan over, but not touching simmering water, whisking constantltly unti muxture stars to thicken. If at any time it gets to thick remove from heat and add drops of water from the simmering pan

Off heat whisk in melted butter, very slowly to keep it thick

Remove to a small heat proof bowl. It can be kept warm for up to 1 hour in a pan of hot, not simmering water. If it gets thick add drops of hot water, whisking to thin

Serve sauce on grilled cauliflower