In a pot, heat the oil over medium heat. Add the onion and garlic, then cook, stirring occasionally, until soft (about 3 minutes).
Add the broth, smoked paprika, crushed tomatoes, grape tomatoes, chipotle, sugar, lime juice, and season with salt and pepper. Cover with a lid and bring to a simmer for 15 - 20 minutes, stirring.
Taste and adjust the seasoning with salt and sugar as needed.
Whisk the flour with an equal amount of water to form a smooth paste (use a little more flour and water if needed to thicken).
Slowly stir the flour/water mixture into the simmering soup until it reaches a creamy consistency. Remove from heat and stir in the chopped cilantro.
Serve with tortilla chips. Garnish with cilantro.