1/4 cup slivered almonds
12 ounces cherry or grape tomatoes (about 2 1/2 cups)
1/2 cup packed fresh basil leaves
1 medium garlic clove , minced or pressed through garlic press (about 1 teaspoon)
1 small pepperoncini (hot peppers in vinegar), stemmed, seeded, and minced (about 1/2 teaspoon) (see note)
Pinch red pepper flakes (optional)
1/3 cup extra-virgin olive oil
1 pound pasta , preferably linguine or spaghetti
1 ounce Parmesan cheese , grated (about 1/2 cup), plus extra for serving
Toast almonds in small skillet over medium heat, stirring frequently, until pale golden and fragrant, 2 to 4 minutes. Cool almonds to room temperature.
Process cooled almonds, tomatoes, basil, garlic, pepperoncini, 1 teaspoon salt, and red pepper flakes (if using) in food processor until smooth, about 1 minute. Scrape down sides of bowl with rubber spatula. With machine running, slowly drizzle in oil, about 30 seconds.
Meanwhile, bring 4 quarts water to boil in large pot. Add pasta and 1 tablespoon salt and cook until al dente. Reserve ½ cup cooking water; drain pasta and transfer back to cooking pot.
Add pesto and ½ cup Parmesan to cooked pasta, adjusting consistency with reserved pasta cooking water so that pesto coats pasta. Serve immediately, passing Parmesan separately. Serves 4-6, so don’t be afraid to cut it down!