Wash and dry all produce. Peel, then cut shallot into 1/8-inch pieces.Cut tomato into 1/4 inch pieces.Add half the vinegar, 1/2 tsp (1 tsp) sugar and 1 tbsp (2 tbsp) oil to a large bowl . Season with salt and pepper then stir to combine. Add tomatoes and half the shallots. Stir to coat.

Heat a large non-stick pan over medium-high heat. While pan heats, cut and discard the top 1 inch of lemongrass, leaving the root end in tact.Remove outer layer of lemongrass, then quarter lengthwise. Using the back of a spoon or a heavy pot, forcefully tap the lemongrass to bruise. Finely chop lemongrass.

When the pan is hot, add 1 tbsp (2 tbsp) oil, lemongrass and remaining shallots. Cook, stirring often, until golden-brown and fragrant, 1-2 min. Add chicken. Cook, breaking up chicken into smaller pieces, until no pink remains, 4-5 min.**Add sweet chili sauce, fish sauce and remaining vinegar. Season with salt and pepper, to taste. Cook, stirring often until fragrant, 30 sec.Remove from heat and allow to cool for 3-4 min.

Pick mint leaves from stems, then roughly chop.Stir half the mint into cooled chicken mixture.Thinly slice cucumber.Add cucumbers and spring mix to the bowl with tomatoes and shallots. Toss to coat.

Divide salad between plates.Top with chicken mixture. Drizzle chili-garlic sauce over top.Sprinkle crispy shallots and remaining mint over top.