Slice the onions thinly into half moons and place them in a large air fryer or oven-safe baking dish.

Grate the zest of one unwaxed lemon over the onions and grate in a garlic clove. Drizzle with a little olive oil and toss everything together.

Halve the zested lemon and nestle it amongst the onions.

Cook:
In the air fryer:  10 minutes at 170°C (340°F), stirring once to brown the onions evenly. There is no need to preheat
In the Oven: Preheat your oven to 180°C (350°F).
Roast in the preheated oven for 15 minutes at 180°C (350°F), or until the onions are golden brown and soft.

While the onions are cooking (either method), pour boiling water over the pearled spelt in a separate bowl. Let it sit for 5 minutes to soften a touch. Drain the water.

Remove the onions from the air fryer or oven.

Drain the pearled spelt and add it to the baking dish with the onions. Squeeze the roasted lemon over the dish, releasing all the juice and flesh over the grains. Discard the remaining lemon and remove any seeds that fall in.

 Pour the stock over the grains, check the seasoning and stir to combine.

Return the dish to the air fryer or oven to cook.
In the Air Fryer:
Cook for an additional 15-20 minutes at 170°C (340°F). Until the spelt grains are soft and tender
In the oven: Cook for an additional 20-25 minutes at 180°C (350°F), or until the spelt is tender.
While Cooking: Check the liquid. As dishes vary in shape, and thus speed of evaporation, you may need to top up with more stock to keep grains nice and submerged.

While the spelt cooks, thinly slice the asparagus stems, leaving tips (the last 3-4cm) whole.

Once the spelt is cooked, add the asparagus tips, sliced stems, grated Parmesan cheese, chopped parsley, and creme fraiche to the dish. Stir everything together gently.

Cook for an additional 5 minutes in the air fryer or oven, or until the asparagus tips are al dente (tender but crisp). Check the consistency of your grain risotto, adding a further splash of water or stock to achieve a nice loose, but not runny, risotto-like consistency

Season with additional salt and pepper to taste, spoon onto plates, top with more parmesan if desired, a sprinkle of pistachios, and a drizzle of oil.