For the cajeta: Split the vanilla bean in half and, using the back of a knife, scrape the seeds away from the pod halves
Add the seeds, the pod halves, the goat’s milk, sugar and vanilla to a pot. Bring to a simmer and remove from the heat. Add the baking soda—be careful; it will bubble. Place the pot back on the heat and simmer until it reaches a deep golden-brown caramel color.
Strain through a fine-mesh strainer or chinois and let cool to room temperature. (Refrigerate any leftover cajeta for other uses—it tastes good on absolutely everything!)
Chill four small plates.
Carefully remove any connective tissue from the goat meat and discard. Wrap the meat tightly in plastic wrap and place in the refrigerator.
In a small mixing bowl, gently mix all of the crab salad ingredients together and reserve in the refrigerator.
Clean any bruised leaves from the Brussels sprouts and trim the bottoms. Gently remove the first layer of leaves from each and reserve. Quarter the sprouts. In a pot of boiling salted water, blanch the leaves for a few seconds then place them in ice water to shock (stop the cooking). Dry the leaves on a towel.
Blanch the quartered sprouts for 1 minute, until still firm in the center, then shock in ice water. Drain and dry.
Remove the goat meat from the refrigerator, dice finely with a sharp knife and place in a bowl. Cover the bowl with plastic wrap and return to the refrigerator.
Heat the olive oil for the Brussels sprouts to the smoking point in a small sauté pan, add the sprouts, one by one, and caramelize the interior of the vegetable. Season with kosher salt.
Remove the meat from the refrigerator and season with the olive oil, salt and pepper.
Spoon the cajeta onto the chilled plates. Using the ring mold, place a quarter of the goat tartare on each plate then place a dollop of crab salad on top. Place the caramelized Brussels sprouts around each plate and garnish with blanched Brussels sprout leaves. Serve with crostini, crackers, chips or bread.