Cook tagliatelle in large pot of boiling salted water until just tender but still firm to bite. Drain, reserving 1 cup pasta water. Return pasta to same pot.
Meanwhile, heat olive oil in large sauté pan over medium-high heat. Add 1/2 cup basil, garlic, and dried chili flakes; stir 1 minute.
Start out by adding 1/2 cup reserved hot pasta water and boil until slightly reduced, about 3 minutes.
Add the cooked tagliatelle, remaining 1/2 cup basil, lemon juice, and cheese, tossing over medium heat until sauce coats pasta. Add additional reserved pasta water if dry .
Season with salt and pepper to taste. Excellent on its own or serve with grilled chicken or shrimp.
For the caprese salad, season the slices of tomato lightly with salt and pepper.
Top each slice of tomato with a slice of fresh mozzarella. Garnish the top with fresh basil leaves.
Season again with additional salt and pepper, drizzle with olive oil, and serve.