Bring a large pot of generously salted water to a rolling boil (use 2 tablespoons salt for 6 quarts water—this seasons the pasta from within). Add tortellini and cook according to package directions until al dente, usually 7–9 minutes for fresh or 3–5 minutes for frozen. Stir gently once after adding to prevent sticking.

Critical step: Reserve ½ cup of starchy pasta water before draining. Then immediately transfer tortellini to a large bowl of ice water to stop cooking. Let sit 2 minutes until completely cold—this prevents overcooking and locks in perfect texture. Drain thoroughly in a colander, shaking well to remove excess water. Never rinse pasta with tap water—it removes surface starch needed for dressing adhesion.

While pasta cooks, prepare pesto. In a food processor, pulse toasted pine nuts and garlic until finely chopped. Add 2 cups of basil leaves and pulse 5–6 times until coarsely chopped. Add Parmesan, lemon juice, lemon zest, salt, and pepper. Pulse to combine.

With processor running, slowly drizzle in olive oil through the feed tube until smooth and emulsified. Scrape down sides and pulse again. Taste and adjust: needs more brightness? Add another teaspoon lemon juice. More saltiness? Add 1 tablespoon extra Parmesan. For creamier texture (ideal for pasta salad), blend in 2–3 tablespoons of the reserved starchy pasta water—it creates a silky emulsion that clings beautifully to tortellini.

Drain tortellini well and return to the empty pot (off heat). While still slightly warm—not hot—add half the pesto sauce. Gently fold with a silicone spatula until every piece is evenly coated. The residual warmth helps the pasta absorb the pesto’s flavors deeply. Let cool completely at room temperature, stirring occasionally, about 15 minutes.

Pro tip: This warm-dressing technique is the difference between a good pasta salad and a great one. Cold pasta repels oil-based dressings, causing separation. Warm pasta welcomes the pesto, creating flavor integration that lasts for days.

Once tortellini has cooled completely, transfer to a large serving bowl. Add sun-dried tomatoes, mozzarella pearls, halved cherry tomatoes, sliced basil, toasted pine nuts, diced red onion, and olives (if using). Pour remaining pesto over the top.

Gently fold everything together using a folding motion—don’t stir vigorously or you’ll break the delicate tortellini and crush the mozzarella. The goal is even distribution without sacrificing texture. For best results, fold in two stages: first combine tortellini with sturdy ingredients (sun-dried tomatoes, onions), then gently fold in delicate items (mozzarella, fresh tomatoes, basil).

Cover the bowl tightly with plastic wrap pressed directly onto the salad’s surface (this prevents oxidation and drying). Refrigerate for at least 1 hour—but ideally 3–4 hours—to allow flavors to meld. The acid from tomatoes and lemon juice gently “cooks” the ingredients, creating a harmonious flavor profile that’s greater than the sum of its parts.

Important: Do not add extra basil or delicate garnishes until serving time. They’ll turn dark and slimy if added too early. The salad tastes better on day 2 as flavors deepen—but consume within 2-3 days for optimal texture and food safety.

Before serving, bring salad to cool room temperature (15–20 minutes out of refrigerator)—chilled food numbs taste buds and dulls flavors. Gently fold in any accumulated liquid at the bottom of the bowl to redistribute dressing.

Transfer to a serving platter or individual bowls. Garnish with fresh basil leaves, shaved Parmesan, and cracked black pepper. Serve with lemon wedges on the side for guests to add brightness to their liking. For picnics, pack in an insulated cooler with ice packs—this salad stays delicious for up to 4 hours unrefrigerated thanks to the olive oil’s preservative qualities.