Risoni, orzo, same thing. Rice shaped pasta that behaves like risotto if you cook it the way you would cook risotto, which is what happens here.
Thirty minutes, one pan, and the pasta cooks directly in stock and cream so it goes creamy without any stirring ritual or ladling. Chicken cooks first in the same pan, comes out, and goes back in at the end.
Two chicken breasts cut through the middle to make four thinner steaks.

A whole breast takes fifteen to twenty minutes to cook through and the outside overcooks long before the middle catches up. Halved horizontally, each piece cooks in eight minutes total and stays juicy right through. It also gives you four portions from two breasts, which is where the value in this dish comes from.
The marinade is dry spices and oil rubbed in by hand. Garlic, Italian herbs, paprika, salt and pepper. No acid, no liquid, nothing that needs time to work, so you can cook it straight away.
In the last two minutes of cooking the chicken, add sixty millilitres of water to the pan.
Everything stuck to the base is browned chicken and toasted spice, and that is the flavour foundation for the whole dish. Water loosens it and lifts it back into the pan. Two minutes later it has cooked off again and left all of that behind for the risoni to pick up.
Then the chicken comes out and rests on a plate while the pasta cooks.
This matters more than it usually does. Cast iron, a heavy based casserole, or a thick bottomed deep frying pan.
Thin cookware heats unevenly, which means parts of the pan run hot and boil the liquid off too fast while other parts barely simmer. You end up with pasta that is cooked in some places and hard in others, or with far too much or too little liquid at the end.
Keep it at a gentle simmer with small bubbles for the entire ten to twelve minutes. If it stops bubbling, raise the heat slightly. If it is rolling, drop it. That steady simmer is what cooks the pasta evenly.
Eighty grams goes in with the risoni and they are doing more than adding tomato flavour.
They are concentrated, salty and slightly sweet, and they release all of that into the cream as everything simmers. Dijon mustard and lemon juice go in at the same time, which sounds like a lot of sharp things against cream, and it is exactly right. Two cups of cream and stock need acid or the whole dish sits heavy.
Spinach and parmesan go in with the pan off the heat entirely.
The spinach wilts in the residual warmth in under a minute, and taking it off the heat stops the parmesan splitting. Then the chicken goes back in, sliced if you like, and the whole thing sits covered for two or three minutes so everything comes back up to temperature together.
If the risoni is stiff and clumping rather than saucy, add a tablespoon or two of boiling water from the kettle and stir hard. Repeat until it loosens.
Pasta keeps absorbing liquid after cooking, so this is normal rather than a mistake, and it is fixable in about ten seconds.
Leftovers keep three days refrigerated and taste better the next day. The oils may separate on reheating. Stir in a spoonful of stock or water over low heat and it comes back together. Do not freeze it, the chicken dries out.

Anything that cooks quickly can go in with the risoni. Peas, chopped asparagus or sliced mushrooms all work. Harder vegetables should be cooked separately first, since ten minutes at a gentle simmer will not soften them.
Slice the chicken into bite sized pieces first, then warm everything in a pan over medium-low with one or two tablespoons of stock stirred in. Cover and give it four or five minutes. If the sauce splits, more stock and vigorous stirring brings it back.
A one pan creamy tomato chicken risoni with sun-dried tomatoes, dijon, lemon, spinach and parmesan.
Nutrition per serving from source: 778 calories, 48g fat, 24g saturated fat, 142mg cholesterol, 846mg sodium, 1386mg potassium, 59g carbohydrates, 5g fiber, 13g sugar, 31g protein. Use heavy based cookware; thin pans heat unevenly and leave the pasta unevenly cooked. Keep the liquid at a gentle simmer the entire cooking time. If the risoni is too stiff, loosen with 1 to 2 tablespoons of boiling water at a time. Keeps 3 days refrigerated. Not suitable for freezing.