Make the jalapeño pesto: Place the jalapeños, serranos, onions, almonds and olive oil in a food processor and process until smooth. Season with salt to taste.
Bring 8 cups of water to boil in a large pasta pot.
While the water is heating, combine the olive oil and the garlic in a 12- to 14-inch sauté pan, and sauté over medium-high heat until the garlic is almost brown, about 3 minutes. Add 1 1/2 cups of the jalapeno pesto and bring to a simmer.
When the water comes to a boil, add 2 tablespoons salt. Drop the pasta into the boiling water and cook for 1 minute less than the package instructions indicate. Just before the pasta is done, carefully ladle 1/4 cup of the cooking water into the pan containing the jalapeño mixture.