Break down the charcuterie board into categories: meat, cheese, crunch, pickle/briny, and sweet/fruity.
Slice a plump red onion thinly and place it in a 1-quart mason jar or any large container that isn't metal.
Separately, in a medium-sized pot, add 2 cups (480 milliliters) of white vinegar, 1 cup (240 milliliters) of water, and 2 tablespoons (25 grams) of kosher salt. Bring that to a boil over medium-high heat.
As soon as it hits a boil, take it off the heat and pour it over your onions. It should just about cover the onions.
Use some plastic wrap to adhere to the surface of the liquid to keep everything submerged. Let it rest at room temp until completely cool.
Slice a clove of garlic in half to expose a fresh cut edge.
Rub the garlic end all over each slice of the toasted bread to perfume it.
Slice a tomato in half and scrub it all over the bread.
Combine one cup (225 grams) of granulated sugar and one cup (240 milliliters) of water in a small pot. Bring that to a boil over high heat until it becomes syrupy.
Separately thinly slice two habanero chilies, one serrano chili, and a shallot over a mandolin.
Once your mixture is ready, let it cool for three minutes, then pour your gastrique over the sliced vegetables.
Hit the gastrique with some fresh cracked black pepper and let it sit until completely cool.
Arrange the cheese, meats, pickles, and crackers/bread on the charcuterie board.