Warm oil in a large skillet over medium heat. Add garlic and cook, stirring, 1 to 2 minutes, until fragrant (reduce heat to medium-low if garlic starts to brown). Add tomatoes, salt, and optional herbs, if using, and increase heat to medium-high. Cook, stirring, for 3 minutes. Increase heat to high and continue to cook, stirring. The tomatoes will start blistering and popping; help them along by crushing them with the back of a wooden spoon. Cook, stirring, 5 to 7 minutes, until tomatoes take on a jammy consistency. Remove from heat. Discard herbs and cool mixture. Taste and adjust seasoning as necessary, adding sugar if desired.