Prep everything first: finely dice the onion, carrot and celery (classic soffritto). Mince the garlic. Measure the cooked red lentils, crush tomatoes, herbs and oils. Having everything ready keeps the cooking rhythm tight and prevents overcooking delicate aromatics.

Bring a large pot of well‑salted water to a vigorous boil for the pasta. Salt should make the water taste like seawater — this is your only chance to season the pasta itself. Keep the water at a rolling boil and ready so you can add the spaghetti later without waiting.

Heat a large, heavy skillet or shallow pot over medium heat and add 4 tablespoons (60 ml) olive oil. When the oil shimmers (not smoking), add the diced onion, carrot and celery with a pinch of salt. Sweating the soffritto gently (6–8 minutes) on medium‑low releases sweetness and builds the aromatic backbone of the sauce; don’t rush with high heat or you’ll brown and lose that soft sweetness.

Add the minced garlic, dried oregano, thyme and red pepper flakes. Cook 30–45 seconds, stirring — this quick burst blooms the dried herbs and garlic in oil and releases their fragrant oils without burning them (burnt garlic tastes bitter).

Pour in the crushed tomatoes and the bay leaf, scraping up any browned bits from the pan. Add 120 ml vegetable broth or water to loosen the sauce if it feels too thick. Simmer gently for 8–10 minutes uncovered — this reduces raw tomato brightness, integrates the flavors and thickens the sauce slightly. A gentle simmer (not a furious boil) keeps the sauce glossy and prevents it from separating.

Stir in the cooked red lentils and lower the heat to medium‑low. Cook the mixture 8–10 minutes, stirring occasionally so lentils absorb tomato flavor. The lentils add body and protein; cooking them in the sauce lets them pick up acidity and herbs so they don’t taste flat.

Season the sauce with 1 teaspoon salt (adjust later) and several grinds of black pepper. Remove the bay leaf. Taste and adjust acidity with a pinch of sugar if the tomatoes are very bright, or a splash of vinegar if they need lift. Let the sauce continue to gently reduce until it’s thick enough to coat the back of a spoon.

When your pasta water is boiling, add the whole‑wheat spaghetti and cook 1–2 minutes less than package directions for al dente. Whole‑wheat pasta benefits from slightly undercooking because it will finish cooking when tossed with the sauce and pasta water; this prevents a dry, chalky bite.

Before draining, reserve 1½ cups (about 360 ml) of the starchy pasta cooking water. Starchy water is the secret emulsifier: its dissolved starch helps the sauce cling to the pasta and builds a silky finish when combined with the sauce and a touch of fat.

Drain the spaghetti and add it directly to the skillet with the lentil bolognese. Add ½ to 1 cup (120–240 ml) of reserved pasta water and toss vigorously over low heat for 1–2 minutes. The pasta water loosens the sauce and, when reduced a little, creates a glossy emulsion that coats each strand. If the pan looks dry, add more water in small splashes; you want a clingy, not soupy, sauce.

Stir in the grated Parmesan (or 1 tbsp nutritional yeast per serving for a vegan option) off the heat; the residual heat melts the cheese into the sauce and enriches the texture. Finish with a drizzle (optional) of extra virgin olive oil and a final grind of black pepper. Taste and adjust salt.

Toss the mixed salad greens with the vinaigrette: in a small bowl whisk 20 ml olive oil, 20 ml red wine vinegar (or lemon juice), 1 tsp Dijon, and a pinch of salt and pepper. Dress just before serving so the greens stay crisp.

Plate: twirl a portion of spaghetti into warm shallow bowls, spoon extra lentil bolognese on top or to the side, and finish with a sprinkle of Parmesan or nutritional yeast and a few red pepper flakes if desired. Serve with the dressed mixed greens on the side.

Leftovers and storage: cool sauce quickly, store cooled sauce and pasta separately in airtight containers in the refrigerator for up to 3 days. Reheat gently in a skillet with a splash of water to loosen; reheat pasta very briefly to avoid becoming gummy.