How to  Make a Chaï-Infused Sweet Vermouth: 

• 4 green cardamom pods
• 4 whole cloves
• 1 cinnamon stick
• 1 tablespoon peeled and coarsely chopped ginger
• 1 tablespoon loose-leaf chai tea (black)
• 1-liter bottle of sweet vermouth 

1. Place the cardamom, cloves, cinnamon, and ginger in a small saucepan over low heat and heat until fragrant, about 2 minutes.
2. Add the tea leaves and 1 cup of vermouth (approx. 8 oz/240 ml).
3. Bring to a low boil for 2 minutes.
4. Remove from the heat and let cool to room temperature.
5. Once the mixture has cooled down, add the remaining vermouth to the saucepan and refrigerate for 1 hour.
6. Once an hour has passed, take the mixture out of the fridge and fine-strain it.
7. Bottle and store in the fridge for up to 6 months.

Substitutes:

• Cognac: If you don't have cognac, you can use another type of brandy to make this cocktail. You can use Armagnac for a similar flavor profile or switch to applejack or Calvados for a fruitier, slightly sweeter cocktail.
• Chai-Infused Sweet Vermouth: See the recipe above. You can use plain sweet vermouth if you’re in a hurry, but this will affect the end result and won’t make for an equally balanced & interesting cocktail.
• Fresh Lemon Juice: Bottled lemon juice can work, but fresh is always best for that vibrant citrus kick. Fresh lime juice can also do the trick if you have any.
• Pomegranate Juice: Cranberry juice can be an alternative if you don't have pomegranate juice on hand; it adds a different but still delightful tartness.
• Simple Syrup:  If you don't have any simple syrup, you can easily make some at home by mixing together equal parts of sugar (any kind you like) and hot water. Stir well to dissolve and let it cool down before using it. In the refrigerator, this homemade simple syrup will last for about a month. Honey syrup (2 parts honey to 1 part warm water) or agave nectar can be used as natural sweeteners if you prefer not to use simple syrup.

Making a Pitcher of Mata Hari Cocktail:

• Scale: To make a pitcher that serves 8, multiply all the ingredients by 8. That would be 10 oz of cognac, 8 oz of chai-infused sweet vermouth, 6 oz of fresh lemon juice, 6 oz of pomegranate juice, and 4 oz of simple syrup.
• Mix: In a large pitcher, combine the cognac, chai-infused sweet vermouth, lemon juice, pomegranate juice, and simple syrup. Add ice and stir well. Give it a taste and stir a bit more if you feel like more dilution is necessary.
• Serve: Strain to remove the ice, serve immediately into chilled Martini or coupe glasses, and garnish each glass with dried rosebuds. If you have some leftovers, be sure to keep them in the fridge (make sure no ice cubes are left inside) in an airtight container.

Making it Non-Alcoholic:

• Cognac Substitute: Use a non-alcoholic brandy substitute; these are available and do a reasonable job mimicking the brandy's depth. You can also use unsweetened grape juice as a substitute, or make your own substitute using black tea: brew a very strong batch of black tea (English Breakfast or Darjeeling, for example), let it cool down to room temperature before using, and store in the fridge if you have any leftovers. Whatever substitute you decide to use, you can infuse it with chai spice (see recipe above) as well for a stronger, spicier taste in your cocktail.
• Chai-Infused Sweet Vermouth Substitute: You can follow the recipe above using non-alcoholic sweet vermouth.
• Proceed As Usual: Use these non-alcoholic substitutes instead of the regular ingredients, follow the original steps, and enjoy a non-alcoholic version.