Add <quantity>2</quantity> whole chicken breast to a large pot

Add enough water to cover the chicken

Trim, peel and chop <quantity>1</quantity> onion in half. Chop one half again

Peel <quantity>2</quantity> garlic cloves

Add the <quantity>¼</quantity> onion and the garlic cloves to the pot. Simmer for 30m until the chicken breasts are cooked

Slice <quantity>2</quantity> garlic cloves

Slice <quantity>½</quantity> onion

Chop <quantity>6</quantity> tomatoes into large pieces

Hache <quantity>3</quantity> canned chipotle chiles

Remove the skin and the bones from the cooked chicken breasts

Shred the chicken and reserve

Reserve broth from the top of the pot

Add <quantity>3<unit>tbsp</unit></quantity> of vegetable oil to a medium pot over medium heat

Add the sliced onion

Add the sliced garlic and stir. Cook until translucent

Add the chopped tomatoes and stir. Cook until the tomatoes begin to release their juices

Add the chipotle and stir to combine

Season with salt to taste and add <quantity>¼<unit>cup</unit></quantity> of the chicken broth

Add the shredded chicken and stir

Add <quantity>¼<unit>cup</unit></quantity> of the chicken broth. Stir, add salt to taste and plate it. The chicken tinga is ready

Spread <quantity>1<unit>tbsp</unit></quantity> of sour cream on <quantity>1</quantity> corn tostada

Cover it with chicken tinga

Finish it with <quantity>1<unit>tbsp</unit></quantity> of queso fresco and finely sliced lettuce. The chicken tinga tostada is ready. Enjoy!