In a small bowl, whisk together vinegar, honey, tomato paste and chile flakes. Set aside.
Heat a large 10- to 12-inch sauté pan over medium-high heat. Add oil and shallot and sauté for 1 minute, until translucent. Add chard stems to pan and sauté for about 1 minute. Add chard leaves, stir and continue to cook for another 2 minutes. Season with salt and black pepper and pour mixture into a bowl.
Return pan to heat and pour tomato paste mixture into pan. (Be careful: Vinegar will boil immediately, resulting in strong fumes. Keep your face away from pan.) Stir well and allow liquid to reduce for about 30 to 60 seconds so that it thickens enough to coat the back of a spoon. Remove from heat.
Place chard onto a serving platter and drizzle with sauce. Serve immediately.