In bowl of food processor, add onion, jalapeño peppers and garlic; Process until smooth, about 2 minutes.
Heat oil in medium skillet over medium-high heat; add pureed onion mixture and cumin. Cook until mixture turns light golden brown and fragrant, stirring occasionally, about 5 minutes. Stir in tomato sauce and 1 cup water; bring to boil. Cook until sauce thickens, stirring occasionally, about 15 minutes more; season with Adobo; keep warm. (Note, to make sauce head of time, see tip below).
Heat oven to 200F. Heat 1 tsp. oil in medium skillet over medium-high heat. Add one tortilla; cook until tortilla inflates and turns light golden on both sides, flipping once, about 2 minutes. Transfer tortilla to large sheet of foil. Repeat with remaining tortillas, adding oil in 1 tsp. measurements if pan becomes dry. Loosely wrap tortillas in foil and transfer to oven to keep warm.
Divide remaining 2 tbsp. oil between 2 medium skillets over medium-high heat. Add 4 eggs to each skillet; season with adobo. Cook eggs until whites are set and yolks are runny; about 3 minutes.
To assemble Huevos Rancheros, divide tortillas between 4 serving plates; spread each tortilla with 2 tbsp. refried beans. Top each with 2 eggs; drizzle with sauce, then sprinkle with cheese. Serve with slices of avocado, if desired.
Making the Ranchera Sauce ahead of time will shave 25 minutes off the total cooking time of this recipe, saving you valuable minutes during a hectic mid-week dinner. To store pre-made sauce (or any left over sauce), transfer to air-tight storage container in the refrigerator for up to 5 days or in the freezer for up to 3 months.