Spice up chicken breasts with a sauce redolent of Mexican flavours in this easy oven-baked dish.
Delicious served with my Mexican 'Green Rice' (which has a cauliflower rice option too to cut down the calories and carbs), and Cheat's Mexican 'Pot' Beans with a dollop of sour cream (or Greek yoghurt if you're counting the calories) and a quick fresh Tomato Salsa (as pictured).
Do something a little bit different for dinner, and easily tailor the heat to suit your tastes.
Serves four, 216 calories per serving.
4 chicken breasts (450g) 
2 onions, sliced (200g) 
3 garlic cloves, sliced 
2 tsp oil (to suit your diet) 
For the sauce
250ml passata (sieved tomatoes) 
2 tbsp chipotle chilli paste (or more/less to taste - I used Discovery brand, as it had a high % of chipotle chillies in it, watch out for tomato-based versions - you can make your own by soaking 3-4 dried chipotle chillies in hot water for 20-30 minutes, then removing seeds and blitzing with a little of the soaking water, if you prefer, e.g. for Paleo etc.) or use a couple of fresh red, de-seeded chillies and blitz the sauce, if you prefer 
3 tbsp tomato puree (double concentrate) 
1 tsp red (or white, or balsamic, or apple cider etc.) wine vinegar 
1 tsp unrefined sugar (or natural/sweetener of choice, optional) 
150ml chicken stock 
1 tbsp (mild) smoked paprika 
Salt to taste, after cooking
Optional fresh coriander leaves to garnish 
Pre-heat your oven to gas mark 5 / 190C (170C fan) / 375F. In a heavy-based, non-stick frying pan, over a low heat, soften the onions and garlic in 1 tsp of the oil (for about 5 minutes), then remove with a slotted spoon and spread over the bottom of an oven-proof dish big enough to fit the four chicken breasts with just a little space between them.
Season the chicken with a little salt, add the second tsp of oil to the frying pan, heat up to sizzling point then brown the chicken quickly on both sides for a few seconds (for flavour), and remove and place on top of the onions.
Thoroughly mix together all the ingredients for the sauce in a jug or bowl (a whisk is good to combine them properly), and have a quick check to see whether you're happy with the heat levels - if you want it mild, just add 1 tbsp chipotle paste to start with - if you want it hotter, then add more to taste.
Pour the sauce all over the chicken and onions (making sure each chicken breast is coated), and place in the oven (uncovered) for 20 to 30 minutes until cooked all the way through (check the thickest part of the biggest chicken breast if unsure) - I actually experimented with a temperature probe cooking this dish, with good results - see here for more on that and which one I used - you can see how well the chicken was cooked in the photo below.
Remove the chicken and plate up, give the remaining sauce and onions a quick stir, have a taste and add salt if required to taste, and pour over the chicken. Enjoy!