Russula parvovirescens (spp., virescens-crustosa) aka Grill Brittlegill.
I fell in love with this wildmushroom many years ago while foraging the wilds of NYC and northern New Jersey. It’s a beautiful mushroom that requires patience to forage enough for a meal for it fruits erratically.
This fungus is mychorrizal with hardwoods such as the oak that these were growing under. The stem is smooth, white, and brittle with an even thickness. The gills are close, a cream/white color, attach to the stem and yield a cream-colored spore print. The cap starts off convex but will open and flatten with age. It is covered in fairly large crustose patches and is radially lined at the margin. The color is mixed shades of green, aqua, teal, and blue. Gazing at the patchwork cap often reminds me of the white capped waves of Caribbean waters.
My favorite way to cook and eat these is to pan sear in butter until crisp on the outside then mix them with grilled shrimp for tacos.