Liquid. Many recipes replace 0.5-1 cup of water with beer or wine. The beer taste should be balanced and not overly hoppy. I’ve seen recipes with white and red wines equally often, but in the case of whites, I’d stay away from oaked ones. Wine is used to add a little bit of fruitiness and tartness to the final taste.
Vegetables. Main vegetables for festive version: onions, garlic, sweet peppers, and tomatoes. Optional vegetables: potatoes, turnip, green beans. I also added untraditional kohlrabi, young golden(!) beets, and parsnip — they all work here well, contributing nice earthy aromas to the complexity of the dish. If you start with whole tomatoes, they need to be peeled before serving. Another option is to use whole peeled canned tomatoes.
Herbs and spices. This group of ingredients is what makes this dish amazing! Salt and black pepper are for seasoning. This dish is not supposed to be very spicy hot, but it requires some heat from red chili peppers. They can be added as dry flakes/powder as well as fresh sliced or slit. The amount depends on your personal preferences.
Adding dry or fresh herbs depends on the season and availability. Fresh herbs are usually used whole and removed from the soup before eating. The more variety of herbs in the dish, the better. I often use a little bit of powdered blue fenugreek (nutty-flavored herb) or the whole Georgian spice mix khmeli suneli in my khashlama, even though it’s just an option. Imeretian saffron (safflower) or real saffron, on the other hand, are a must.