Soak 1 1/2 cups basmati rice in cold water, 15 minutes; drain. Heat 1 tablespoon vegetable oil in a saucepan over medium-high heat. Add 2 teaspoons cumin seeds; cook 30 seconds. Add 1 chopped onion and cook, stirring, 5 minutes. Add 2 1/4 cups water, 1 teaspoon kosher salt, the rice and 3 strips lemon zest. Bring to a simmer, cover and cook over low heat, 15 minutes. Let stand off the heat, 10 minutes. Stir in 1/4 cup toasted sliced almonds, and lemon juice to taste.