Coconut rice pudding

This was simply delicious, not too sweet, with a touch of coconut flavor. Amazingly tasty! Thanks to Chef John for the idea.

Ingredients
1.5 tbsp butter
2/3 cup arborio rice
1 can (400mL) coconut milk
4 cups + 0.25 cup milk
1/3 cup sugar
0.25 tsp vanilla
salt
1 egg yolk

Preparation
Melt the butter in a pot on medium heat. In a separate pot, heat the 4 cups milk and the coconut milk nearly to its boiling point.

 Add the rice to the melted butter and cook for 1-2 minutes, until very lightly browned.

Scoop in about a quarter cup of milk into the rice, let it absorb, stirring constantly. Continue ladling in the milk until the rice is slightly softened, letting it absorb between every scoop. After about 10 minutes add the sugar. Keep cooking until the rice is the desired softness.

Mix the 0.25 cup milk with the egg yolk, add to the ready rice pudding, bring back to a simmer. Add the vanilla and a tiny pinch of salt. Ladle into 6 small ramekins. Cover with foil, pressing it into the top, to prevent membrane formation. Serve chilled.