If your almonds aren't already toasted, spread them on a baking sheet and pop them into a 350-degree oven for about 7 minutes. Give them a toss halfway through so they brown evenly on all sides. You'll know they're ready when they turn a light golden color and smell nutty and warm.
Add the basil, toasted almonds, Parmesan, garlic clove, lemon juice, and olive oil to your food processor. Pulse everything together until it reaches the texture you like best, whether that's silky smooth or a little chunky. I personally love leaving mine slightly coarse so you get little flecks of basil and almond in every bite.
While the pesto comes together, toss your halved cherry tomatoes with olive oil, minced garlic, salt, pepper, and a pinch of red pepper flakes in a mixing bowl. Set this aside so the tomatoes soak up all that flavor while you cook the pasta. This little step makes a big difference in how flavorful the final dish tastes.
Bring a large pot of lightly salted water to a rolling boil, then add your pasta. Cook it until it's al dente, meaning it still has a slight bite to it, since it'll continue softening slightly once tossed with the warm pesto. Save a splash of the starchy pasta water before draining, just in case you need to loosen the sauce later.
Drain the pasta and return it to the same hot pot. Add the pesto and the marinated cherry tomatoes, then toss everything over medium-high heat until it's all piping hot and well coated. If the mixture looks a little dry, stir in a splash of that reserved pasta water to bring it back together.
Spoon the pasta into individual bowls right away while it's still warm and fragrant. Pass extra grated Pecorino Romano or Parmesan at the table so everyone can add as much as they like. I also like scattering a few whole basil leaves on top for a fresh, pretty finish.