Preheat the oven to 190°C. In a bowl, toss the bread cubes with the olive oil, salt, and garlic until evenly coated. Spread onto a tray in a single layer and bake for 10–15 minutes, turning once, until golden and crisp. Let cool completely. The croutons should be crisp all the way through, not just coloured on the outside. Soft-centered croutons go soggy too fast once dressed. That thorough, all-the-way-through crispness matters directly once the croutons meet the salad's dressing — a crouton crisp only on the surface would soften from the inside out almost immediately.

Pat the chicken breasts dry. If one end is much thicker than the other, lightly pound the thicker part so the breasts cook more evenly. Rub with olive oil, salt, black pepper, garlic powder, and oregano if using. Grill on a hot grill pan, cast iron pan, or outdoor grill over medium-high heat for about 5–7 minutes per side, depending on thickness, until nicely charred and the internal temperature reaches 74°C. Transfer to a plate and rest for 5–10 minutes, then slice across the grain. Do not slice immediately after cooking. Resting keeps the juices in the meat instead of running into the salad. During cooking, the chicken's own juices are pushed toward the centre under real pressure, and that rest period lets them redistribute evenly back through the meat rather than spilling out the moment a knife cuts in too soon.

Using a mortar and pestle, or finely by hand and then mixed in a bowl, mash the anchovies and garlic into a smooth paste. Add the egg yolks, lemon juice, Worcestershire sauce, and Dijon if using. Whisk until combined. While whisking continuously, drizzle in the olive oil very slowly at first, then the neutral oil, building a smooth emulsified dressing. Once emulsified, whisk in the grated Parmesan. If the dressing feels too thick, loosen with 1–3 tablespoons cold water until it becomes pourable but still creamy enough to cling to the leaves. Taste and adjust with black pepper, more lemon if needed, and salt only if necessary. The dressing should be bold and concentrated before it hits the lettuce. Romaine dilutes flavour quickly, so under-seasoned dressing produces a flat salad. That slow initial drizzle is what lets the egg yolks' own emulsifying capacity keep pace with the incoming fat — once enough oil has been successfully bound to establish a stable emulsion, the mixture can accept the remaining oil considerably faster without breaking.

Trim the romaine and cut or tear into large bite-size pieces. Wash and dry very thoroughly. A wet salad is not acceptable here — excess water weakens the dressing and makes it slide off the leaves instead of coating them. Any residual surface water on the leaves dilutes the dressing on contact and prevents it from actually adhering, which is exactly why this drying step is treated as non-negotiable rather than a quick rinse-and-go.

Place the romaine in a large bowl. Add enough dressing to coat the leaves lightly but thoroughly — start with about two-thirds, toss well, then add more only if needed. Add most of the croutons and a small handful of shaved Parmesan, then toss again briefly. Caesar salad should be coated, not saturated. The leaves should look glossy and lightly dressed, not heavy and wet. Adding the dressing gradually, tasting the coverage as you go, rather than pouring it all in at once, protects against oversaturating leaves that were specifically dried to actually hold a light, even coat.

Divide the salad among 4 bowls or plates, or transfer to a large serving bowl. Arrange the sliced grilled chicken on top. Finish with the remaining croutons, shaved Parmesan, and a crack of black pepper. Serve immediately. Reserving a portion of the croutons and Parmesan specifically for this final layer, rather than tossing everything in together, keeps those elements visible and crisp right at the top of the finished plate.