1 cup dried brown lentils (7 ounces)7 1/4 cups water, divided
2 teaspoons finely chopped garlic, divided
6 tablespoons vegetable oil, divided
1 cup long-grain white rice
1 small red onion, finely chopped
1 tablespoon bottled ají amarillo or ají mirasol paste (sometimes labeled "crema")
Bring lentils, 5 cups water, and 1/2 teaspoon salt to a boil in a heavy medium saucepan, then simmer, uncovered, until lentils are just tender, 12 to 25 minutes (depending on age of lentils). Drain, then transfer to a large bowl.
Meanwhile, cook 1 teaspoon garlic in 1 tablespoon oil in another heavy medium saucepan over medium heat, stirring, 1 minute. Add rice and cook, stirring, 1 minute. Add remaining 2 1/4 cups water and 1 teaspoon salt and bring to a boil, then cook, covered, over low heat 20 minutes. Remove from heat and let stand, covered, 10 minutes. Stir rice from top to bottom with a rubber spatula, then stir into lentils.
While rice stands, sautéonion and remaining teaspoon garlic in 1 tablespoon oil in a 12-inch heavy nonstick skillet over medium-high heat until onion is golden, 3 to 5 minutes. Stir in chile paste and cook, stirring, 1 minute. Stir onion mixture into rice mixture.
Heat remaining 1/4 cup oil in skillet over medium heat until hot. Add rice mixture and fry, gently flattening with a spatula, until a golden-brown crust forms on underside, about 3 minutes. Stir rice and fry, flattening it, until a crust forms on underside again, about 3 minutes more. Repeat frying and stirring until bits of crust are dispersed throughout, about 9 minutes more (about 15 minutes total frying time).
Notes: I increased this recipe by 1/3rd for the dinner party. I should have doubled it! I also added more of the aji mirasol paste.