In a large pot, bring the water, cinnamon sticks, cloves and tamarind seeds to a boil over high heat. Reduce the heat and simmer until the cinnamon sticks start to soften, about 10 minutes.
Add the pears, guava paste, apples, prunes and dark brown sugar. Simmer for at least 35 minutes, stirring occasionally.
Ladle the punch into mugs, making sure each cup gets some fruit. Garnish each with a tangerine slice and 1 ounce of tequila or mescal, then serve.