Preheat the oven to 350 degrees. Line a baking sheet with parchment paper and butter the paper.
In a large bowl, use a fork to stir the coconut, condensed milk, salt, vanilla, and almond extract to blend them together. Set aside.
In a clean medium bowl, use a whisk or electric hand mixer to beat the egg white and cream of tartar on low speed until foamy and the cream of tartar dissolves. Whisk vigorously or increase the mixer speed to medium-high and beat until soft peaks form. Whisk or use the mixer to beat in the sugar. Use a rubber spatula to fold half of the whipped egg white into the coconut mixture, then fold in the remaining white. Using an ice cream scoop with a 1/4 cup capacity or a 1/4 cup measuring cup, scoop mounds of the coconut batter onto the prepared baking sheet, spacing the macaroons two inches apart.
Bake until the bottoms of the cookies and the tips of the coconut shreds are light brown, about 17 minutes. Cool the cookies on the baking sheet for 5 minutes. Slide a metal spatula under the macaroons to loosen them from the parchment and transfer them to a wire rack to cool completely.
Make the chocolate coating. In a heatproof container or top of a double boiler, put the chocolate and oil. Place it over, but not touching, a saucepan of barely simmering water. Stir over the hot water until the chocolate melts and is smooth. Remove from over the water and let it cool and thicken slightly, about 10 minutes. Scrape the chocolate coating into a small bowl. Dip the bottom of each macaroon in the chocolate and place each cookie, chocolate bottom facing up or on its side on a wire rack. You will have some chocolate coating leftover for another use or to pour over ice cream. Let the macaroons sit until the chocolate coating is firm, about 1 hour. To speed the firming of the chocolate, refrigerate the macaroons on the rack for about 15 minutes.
Serve cold or at room temperature. Store in the refrigerator in a covered container for up to 5 days.