Rinse, drain and then soak the spelt berries in fresh water for a few hours or overnight. This helps speed up the cooking process significantly, so don't skip! If you're using arborio rice, skip this step.
Heat up your stock in a small saucepan till warm. Keep the lid on and the heat low so not much evaporates. You'll need less stock if you're using rice.
In a large, heavy-bottomed pot like an enameled Dutch Oven, melt your butter or oil. Turn the heat to medium-low, and soften the onion for 5-7 minutes. Add in the garlic and cook for an additional minute, and then add in the salt.
Add in the sliced mushrooms and cook till softened and reduced, about 10-15 minutes. Then add in the spelt berries and toast for about 5 minutes-- you should start to smell a warm, bread-like smell.
Add in the 1/2 cup of sherry or wine and allow to cook off. Then begin to ladle in 1 cup of the stock at a time into the spelt berries and the mushrooms, waiting till it's almost fully absorbed to add the next cup of stock. Stir, and then cover (maybe with a small gap for a little steam to escape) in between each addition. While you're waiting, you can set the table, have a glass of wine, make the salad, etc. Risotto requires patience and about 1.5 hours of slow cooking! If you're using rice, the cooking time might be as short as 30 mins.
While you're waiting for the spelt to absorb the stock, bring another pot of water to a boil. Snap off the hard ends of the asparagus (the last 1/4 of the stalk snaps off easily) and toss those into a freezer bag for asparagus stock. Chop the remaining 2/3rds or 3/4rds of the stalks into 1-1.5" pieces. When the water is boiling, drop in the asparagus pieces. Quickly fill up a bowl with ice water, and by the time you've done that (30 seconds to 1 min) remove the asparagus and quickly add it to the ice water. Allow to totally cool, about 1 more minute, and drain. It should have turned bright green but still have a nice crunch. Follow the same procedure if using broccoli florets, or if you're using kale, skip this step.
Keep going with your stock additions, and at a certain point there will no longer be an white/opaque dot on the spelt and it will seem creamy-- taste to make sure it's cooked but hopefully still has a little bite. Make sure to stir occasionally so it doesn't stick to the bottom.
Right before it's ready to serve, stir in the asparagus (or broccoli or kale), the cheese and the lemon zest. Taste it to adjust seasoning, and serve with some creamy ricotta on the side!