Seared Queso Blanco with Garlicky Mushrooms on Toast

Steps

1. Wash a large pot, slotted spoon, colander and thermometer well, and line the colander with a double layer of clean cheesecloth set over a bowl.
2. Pour the whole milk into the pot and heat over medium, stirring often so it doesn't scorch, until steaming and about 190°F (88°C).
3. Take the pot off the heat and slowly stir in the cider vinegar. Within a minute or two the milk curdles: white curds clump together and separate from thin, clear yellow-green whey. Let the curds rest undisturbed for 10 minutes.
4. Ladle the curds into the lined colander, drain for 5 minutes, then sprinkle with 2 g of the salt and half of the dill and fold gently.
5. Gather the cloth into a tight bundle, flatten it into a disk about 1 inch thick, set it in the colander over the bowl, top with a plate and a heavy can, and refrigerate at 40°F (4°C) or below for 1 hour, until firm enough to slice. You will get about 240 g of cheese, about 60 g per serving; discard or save the whey.
6. Rinse and dry the pot. Unwrap the cheese and cut it into 8 slices.
7. Heat half of the olive oil in the pot over medium-high and sear the cheese slices 2 minutes per side until golden; queso blanco softens but holds its shape. Move them to a plate.
8. Add the remaining half of the olive oil and the mushrooms to the pot and cook 6 to 7 minutes, until browned and their liquid has cooked off. Stir in the garlic for 30 seconds, then add the spinach, the remaining 2 g salt and the black pepper and stir until just wilted.
9. Meanwhile toast the bread until golden and crisp.
10. Top each slice of toast with the mushroom-spinach mixture and a seared cheese slice, scatter with the remaining half of the dill and serve two slices per person.
11. Refrigerate any leftover cheese promptly in a covered container and use within 3 days; do not age it.